Last updated

Vaccine description
Target SARS-CoV-2
Vaccine type Protein subunit
Clinical data
Trade names Zifivax
Routes of
ATC code
  • None
Legal status
Legal status

ZF2001, trade-named Zifivax or ZF-UZ-VAC-2001, is an adjuvanted protein subunit COVID-19 vaccine developed by Anhui Zhifei Longcom in collaboration with the Institute of Microbiology at the Chinese Academy of Sciences. [1] [2] The vaccine candidate is in Phase III trials with 29,000 participants in China, Ecuador, Malaysia, Pakistan, and Uzbekistan. [3] [4]


ZF2001 employs technology similar to other protein-based vaccines in Phase III trials from Novavax, Vector Institute, and Medicago. [5]

ZF2001 was first approved for use in Uzbekistan and later China. [6] [7] Production capacity is expected to be one billion doses a year in China [8] and 200 million in Uzbekistan. [9] By July, 100 million doses had been administered in China and Uzbekistan. [10]

Medical uses

It is administered in 3 doses over a period of 2 months. [8]


In August 2021, preliminary data from a phase III study with 28,500 participants indicated an overall efficacy of 82% against disease of any severity. Efficacy was 93% against the Alpha variant and 78% against the Delta variant. [11] [12]

In July 2021, lab studies showed ZF2001 retained neutralizing effects against B.1.429 (Epsilon), B.1.351(Beta), P.1(Gamma), B.1.525(Eta), B.1.617.1(Kappa), the neutralizing titers decreased ranging from 1.1 fold to 2.1 fold, but the neutralizing efficacy were still good. [13]


According to industry experts, production for this kind of vaccine is stable and reliable, and easier to achieve large-scale industrial production at home and overseas. However it was noted it can be very inconvenient for people to come back for a second and third dose. [8] Subunit vaccines are delivered alongside adjuvants and booster doses may be required. [14]

The company's vaccine manufacturing facility was put into use in September. [15] In February 2021, management said the company had an annual production capacity of 1 billion doses. [8]

In July 2021, an agreement was reached to produce the vaccine in Uzbekistan starting with 10 million doses a month and eventually 200 million doses a year. [9]


Clinical trials

Phase I and II trials and results

In June 2020, Longcom began a double-blind, randomized, placebo parallel controlled Phase I trial with 50 participants aged 18–59 in Chongqing divided into low-dose, high-dose, and placebo groups. [16]

In July, Longcom began a randomized, double-blind, placebo-controlled Phase II trial with 900 participants aged 18–59 in Changsha, Hunan divided into low-dose, high-dose, and placebo groups. [17] In August, an additional Phase II trial was launched with 50 participants aged 60 and above. [18] [1]

In Phase II results published in The Lancet, on the two-dose schedule, seroconversion rates of neutralizing antibodies after the second dose were 76% (114 of 150 participants) in a 25 μg group and 72% (108 of 150) in a 50 μg group. On the three-dose schedule, seroconversion rate of neutralizing antibodies after the third dose were 97% (143 of 148 participants) in the 25 μg group and 93% (138 of 148) in the 50 μg group. 7 to 14 days after the administration of the third dose, the GMTs of neutralizing antibodies reached levels that were significantly higher than observed in human convalescent serum of recovering COVID-19 patients, especially in the 25 μg group. [19]

Phase III trials

In December 2020, Longcom began enrollment of a Phase III randomized, double-blind, placebo-controlled clinical trial for 29,000 participants, including 750 participants between 18-59 and 250 participants 60 and older in China and 21,000 participants between 18-59 and 7,000 participants 60 and older outside China. [20] [15]

In December 2020, Malaysia's MyEG announced it would conduct Phase III trials. If the trials were successful, MyEG would be the sole distributor of ZF2001 in Malaysia for 3 years. [4]

In December 2020, Uzbekistan began a year-long Phase III trial of ZF2001 with 5,000 volunteers between 18 and 59. [21] [22]

In December 2020, Ecuador's Minister of Health, Juan Carlos Zevallos announced Phase III trials would involve between 5,000 and 8,000 volunteers. [23]

In February 2021, Pakistan's Drug Regulatory Authority (DRAP) approved Phase III trials with approximately 10,000 participants to be conducted at UHS Lahore, National Defense Hospital, and Agha Khan Hospital. [24]

The vaccine is also being trialed in Indonesia. [12]

Children and adolescents trial

In July 2021, Longcom began a randomized, blinded, placebo-controlled phase I with 75 participants aged 3-17. [25] [26]

In November 2021, Longcom began a phase II with 400 participants aged 3-17. [27]


  Full authorization
  Emergency authorization

On 1 March 2021, Uzbekistan granted approval for ZF2001 (under tradename ZF-UZ-VAC 2001) after having taken part in the Phase III trials. [7] In March, Uzbekistan received 1 million doses and started vaccinations in April. [28] By June, a total of 6.5 million doses had been delivered. [29]

On March 2021, China approved of ZF2001 for emergency use after being approved by Uzbekistan earlier in the month. [6]

In June 2021, Malaysia's MyEG signed a letter of intent to purchase 10 million doses of the vaccine. [30]

On 7 September, the National Agency of Drug and Food Control of Indonesia (BPOM) published the emergency use authorization for Zifivax. [31]


As described in Cell, the CoV spike receptor-binding domain (RBD) is an attractive vaccine target for coronaviruses but is constrained by limited immunogenicity, however a dimeric form of MERS-CoV RBD offers greater protection. The RBD-dimer significantly increases neutralizing antibodies compared to a conventional monomeric form and protected mice against MERS-CoV infection. CoV RBD-dimer have been produced at high yields in pilot scale production. [32]

Rather than injecting a whole virus, subunit vaccines contains virus particles specially selected to stimulate an immune response. Because the fragments are incapable of causing disease, subunit vaccines are considered very safe. [14] Subunit vaccines in widespread use include the Hepatitis B vaccine and Pertussis vaccine. However, as only a few viral components are included in the vaccine which does not display the full complexity of the virus, their efficacy may be limited. [33]

Related Research Articles

Convidecia Vaccine against COVID-19

AD5-nCOV, trade-named Convidecia, is a single-dose viral vector vaccine for COVID-19 developed by CanSino Biologics. It conducted its Phase III trials in Argentina, Chile, Mexico, Pakistan, Russia, and Saudi Arabia with 40,000 participants.

CoronaVac Vaccine against COVID-19

CoronaVac, also known as the Sinovac COVID-19 vaccine, is an inactivated virus COVID-19 vaccine developed by the Chinese company Sinovac Biotech. It was Phase III clinical trialled in Brazil, Chile, Indonesia, the Philippines, and Turkey and relies on traditional technology similar to other inactivated-virus COVID-19 vaccines, such as BBIBP-CorV, another Chinese vaccine, and Covaxin, an Indian vaccine. CoronaVac does not need to be frozen and both the final product and the raw material for formulating CoronaVac can be transported refrigerated at 2–8 °C (36–46 °F), temperatures at which flu vaccines are kept.

Covaxin Vaccine against COVID-19

Covaxin is an inactivated virus-based COVID-19 vaccine developed by Bharat Biotech in collaboration with the Indian Council of Medical Research - National Institute of Virology.

CoVLP COVID-19 vaccine candidate produced in a plant

CoVLP is a COVID-19 vaccine candidate developed by Medicago and GlaxoSmithKline (GSK). It is a coronavirus virus-like particle vaccine grown in the Australian weed, Nicotiana benthamiana.

Soberana 02 Vaccine against COVID-19

Soberana 02 or Soberana 2, technical name FINLAY-FR-2, is a COVID-19 vaccine produced by the Finlay Institute, a Cuban epidemiological research institute. The vaccine is known as Pasto Covac in Iran, where it has been developed in collaboration with the Pasteur Institute of Iran.

EpiVacCorona EpiVacCorona vaccine against COVID-19

EpiVacCorona is a peptide-based vaccine against COVID-19 developed by the VECTOR center of Virology. It consists of three chemically synthesized peptides that are conjugated to a large carrier protein. This protein is a fusion product of a viral nucleocapsid protein and a bacterial MBP protein. The third phase of a clinical trial, which should show whether the vaccine is able to protect people from COVID-19 or not, was launched in November 2020 with more than three thousand participants.

CureVac COVID-19 vaccine Vaccine candidate against COVID-19

The CureVac COVID-19 vaccine was a COVID-19 vaccine candidate developed by CureVac N.V. and the Coalition for Epidemic Preparedness Innovations (CEPI). The vaccine showed inadequate results in its Phase III trials with only 47% efficacy.

SCB-2019 Vaccine candidate against COVID-19

SCB-2019 is a protein subunit COVID-19 vaccine developed by Clover Biopharmaceuticals using an adjuvant from Dynavax technologies. Positive results of Phase I trials for the vaccine were published in The Lancet and the vaccine completed enrollment of 29,000 participants in Phase II/III trials in July 2021. In September 2021, SCB-2019 announced Phase III results showing 67% efficacy against all cases of COVID-19 and 79% efficacy against all cases of the Delta variant. Additionally, the vaccine was 84% effective against moderate cases and 100% effective against hospitalization.

Sanofi–GSK COVID-19 vaccine Vaccine candidate against COVID-19

The Sanofi–GSK COVID-19 vaccine code-named VAT00002 and VAT00008 is a COVID-19 vaccine candidate developed by Sanofi Pasteur and GSK.

Nanocovax Vaccine candidate against COVID-19

Nanocovax is a Vietnamese COVID-19 vaccine candidate developed by Nanogen Pharmaceutical Biotechnology JSC. It is a subunit vaccine.

Sinopharm WIBP COVID-19 vaccine Vaccine against COVID-19

The Sinopharm WIBP COVID-19 vaccine, also known as WIBP-CorV, is one of two inactivated virus COVID-19 vaccines developed by Sinopharm. Peer-reviewed results show WIBP-CorV 72.8% effective against symptomatic cases and 100% against severe cases. The other inactivated virus COVID-19 vaccine developed by Sinopharm is BBIBP-CorV which is comparably more successful. 1 billion doses are expected to be produced per year.

MVC COVID-19 vaccine Vaccine against COVID-19

The MVC COVID-19 vaccine, designated MVC-COV1901 and also known as the Medigen COVID-19 vaccine , is a protein subunit COVID-19 vaccine developed by Medigen Vaccine Biologics Corporation in Taiwan, American company Dynavax Technologies and the U.S. National Institute of Health.

Viral vector vaccine Type of vaccine

A viral vector vaccine is a vaccine that uses a viral vector to deliver genetic material coding for a desired antigen into the recipient's host cells. As of April 2021, six viral vector vaccines have been authorized for use in humans in at least one country: four COVID-19 vaccines and two Ebola vaccines.

West China Hospital COVID-19 vaccine Vaccine candidate against COVID-19

West China Hospital COVID-19 vaccine is a COVID-19 vaccine candidate developed by Jiangsu Province Centers for Disease Control and Prevention, West China Hospital and Sichuan University.

Walvax COVID-19 vaccine Vaccine candidate against COVID-19

ARCoV, also known as the Walvax COVID-19 vaccine, is an mRNA COVID-19 vaccine candidate developed by Walvax Biotechnology, Suzhou Abogen Biosciences, and the PLA Academy of Military Science. It is approved for Phase III trials in China, Mexico, Indonesia, and Nepal.

Razi Cov Pars Vaccine candidate against COVID-19

Razi Cov Pars is a COVID-19 vaccine candidate developed by the Iranian Razi Vaccine and Serum Research Institute.

COVAX-19 Vaccine candidate against COVID-19

COVAX-19 is a recombinant protein-based COVID-19 vaccine developed by South Australian based biotech company Vaxine. It is under clinical trial in collaboration with the Iranian company CinnaGen.

COVID-19 vaccine clinical research

COVID-19 vaccine clinical research uses clinical research to establish the characteristics of COVID-19 vaccines. These characteristics include efficacy, effectiveness and safety. 24 vaccines are authorized for use by national governments, including six approved for emergency or full use by at least one WHO-recognised stringent regulatory authority; while five are in Phase IV. 204 vaccines are undergoing clinical trials that have yet to be authorized. Nine clinical trials consider heterologous vaccination courses.

Noora (vaccine) Vaccine candidate against COVID-19

Noora is a COVID-19 vaccine candidate developed by Baqiyatallah University of Medical Sciences in Iran.

Soberana Plus

Soberana Plus, technical name FINLAY-FR-1A, is a COVID-19 candidate vaccine produced by the Finlay Institute, a Cuban epidemiological research institute.


  1. 1 2 "Anhui Zhifei Longcom: RBD-Dimer – COVID19 Vaccine Tracker". covid19.trackvaccines.org. Retrieved 27 December 2020.
  2. "COVID-19 Vaccine: ZIFIVAX by Anhui Zhifei Longcom Biopharma, Institute of Microbiology Chinese Academy of Sciences". covidvax.org. Retrieved 27 December 2020.
  3. "Fifth Chinese Covid-19 vaccine candidate ready to enter phase 3 trials". South China Morning Post. 20 November 2020. Retrieved 27 December 2020.
  4. 1 2 Ying TP (7 December 2020). "MYEG to conduct phase 3 clinical trial for China's Covid-19 vaccine in Msia | New Straits Times". NST Online. Retrieved 27 December 2020.
  5. Zimmer C, Corum J, Wee SL (10 June 2020). "Coronavirus Vaccine Tracker". The New York Times. ISSN   0362-4331 . Retrieved 27 December 2020.
  6. 1 2 Liu R (15 March 2021). "China IMCAS's COVID-19 vaccine obtained emergency use approval in China". Reuters. Retrieved 15 March 2021.
  7. 1 2 Mamatkulov M (1 March 2021). "Uzbekistan approves Chinese-developed COVID-19 vaccine". Reuters. Retrieved 2 March 2021.
  8. 1 2 3 4 "China's production bottleneck 'could be eased with latest Covid-19 vaccine'". South China Morning Post. 17 March 2021. Retrieved 18 March 2021.
  9. 1 2 "ZF-UZ-VAC-2001 vaccine to be produced in Uzbekistan". UzDaily.uz (in Russian). Retrieved 28 July 2021.
  10. Liu R (17 July 2021). "China Zhifei's COVID shot largely retains effect against Delta variant-lab study". Reuters. Retrieved 17 July 2021.
  11. "China's Zhifei says unit's COVID shot shows 81.76% efficacy in late-stage trial". Reuters. 27 August 2021.
  12. 1 2 "New Chinese vaccine shows 82% effectiveness against serious Covid-19". The Straits Times. 27 August 2021. Retrieved 28 August 2021.
  13. Zhao X, Zheng A, Li D, Zhang R, Sun H, Wang Q, et al. (August 2021). "Neutralisation of ZF2001-elicited antisera to SARS-CoV-2 variants". The Lancet. Microbe. 2 (10): e494. doi:10.1016/S2666-5247(21)00217-2. PMC   8378832 . PMID   34458880. S2CID   237246788.
  14. 1 2 "What are protein subunit vaccines and how could they be used against COVID-19?". www.gavi.org. Retrieved 27 December 2020.
  15. 1 2 "Another Chinese Covid-19 vaccine enters late-stage human trials with a plan to produce 300 million doses annually". Business Insider. Retrieved 27 December 2020.
  16. Clinical trial number NCT04445194 for "Phase I Clinical Study of Recombinant Novel Coronavirus Vaccine" at ClinicalTrials.gov
  17. Clinical trial number NCT04466085 for "A Randomized, Blinded, Placebo-controlled Trial to Evaluate the Immunogenicity and Safety of a Recombinant New Coronavirus Vaccine (CHO Cell) With Different Doses and Different Immunization Procedures in Healthy People Aged 18 to 59 Years" at ClinicalTrials.gov
  18. Clinical trial number NCT04550351 for "A Randomized, Double-blind, Placebo-controlled Phase I Clinical Trial to Evaluate the Safety and Tolerability of Recombinant New Coronavirus Vaccines (CHO Cells) in Healthy People Aged 60 Years and Above" at ClinicalTrials.gov
  19. Yang S, Li Y, Dai L, Wang J, He P, Li C, et al. (August 2021). "Safety and immunogenicity of a recombinant tandem-repeat dimeric RBD-based protein subunit vaccine (ZF2001) against COVID-19 in adults: two randomised, double-blind, placebo-controlled, phase 1 and 2 trials". The Lancet. Infectious Diseases. 21 (8): 1107–1119. doi:10.1016/S1473-3099(21)00127-4. PMC   7990482 . PMID   33773111.
  20. Clinical trial number NCT04646590 for "A Phase III Randomized, Double-blind, Placebo-controlled Clinical Trial in 18 Years of Age and Above to Determine the Safety and Efficacy of ZF2001, a Recombinant Novel Coronavirus Vaccine (CHO Cell) for Prevention of COVID-19" at ClinicalTrials.gov
  21. Reuters Staff (11 November 2020). "Uzbekistan to carry out late-stage trial of Chinese COVID-19 vaccine candidate". Reuters. Retrieved 27 December 2020.
  22. "Uzbekistan poised to start trials on Chinese COVID-19 vaccine | Eurasianet". eurasianet.org. Retrieved 27 December 2020.
  23. "Ecuador participará en ensayos de una vacuna china contra el covid-19". CNN (in Spanish). 29 December 2020. Retrieved 23 January 2021.
  24. "China's third vaccine enters Pakistan". The Nation. 15 February 2021. Retrieved 28 February 2021.
  25. "A randomized, blinded, placebo-controlled phase I clinical trial of recombinant New Coronavirus virus vaccine (CHO cells) in the safety and tolerability of healthy people aged 3 to 17 years of age". chictr.org.cn. Chinese Clinical Trial Registry. 7 July 2021. Retrieved 7 July 2021.
  26. "Recombinant New Coronavirus Vaccine (CHO Cells) to Prevent SARS-CoV-2 Phase I Clinical Trial (3~17 Years Old)". clinicaltrials.gov. United States National Library of Medicine. 14 July 2021. Retrieved 14 July 2021.
  27. "Clinical Trial of Immunogenicity Bridging of a Recombinant New Coronavirus(COVID-19)Vaccine (CHO Cell)". clinicaltrials.gov. United States National Library of Medicine. 5 November 2021. Retrieved 5 November 2021.
  28. "Uzbekistan receives 1 million doses of ZF-UZ-VAC 2001 vaccine". Kun.uz. Retrieved 28 March 2021.
  29. "Доставлен очередной миллион доз вакцины ZF-UZ-VAC2001". Газета.uz (in Russian). 30 June 2021. Retrieved 13 July 2021.
  30. "MyEG signs LOI to buy 10 million doses of Anhui Zhifei Covid-19 vaccine". The Star. Retrieved 28 August 2021.
  31. "BPOM Setujui Penggunaan Dalam Kedaruratan Vaksin Zifivax". Republika.co.id (in Indonesian). 7 October 2021. Retrieved 7 October 2021.
  32. Dai L, Zheng T, Xu K, Han Y, Xu L, Huang E, et al. (August 2020). "A Universal Design of Betacoronavirus Vaccines against COVID-19, MERS, and SARS". Cell. 182 (3): 722–733.e11. doi:10.1016/j.cell.2020.06.035. PMC   7321023 . PMID   32645327.
  33. Dong Y, Dai T, Wei Y, Zhang L, Zheng M, Zhou F (October 2020). "A systematic review of SARS-CoV-2 vaccine candidates". Signal Transduction and Targeted Therapy. 5 (1): 237. doi:10.1038/s41392-020-00352-y. PMC   7551521 . PMID   33051445.