What do we know so far about the Sinopharm vaccine?

This article was published on
May 18, 2021

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Sinopharm's two-dose COVID-19 vaccine was shown to have an efficacy rate of roughly 79% to protect against symptomatic and hospitalized infections. Controversy over the lack of published data about the vaccine has continued despite Sinopharm receiving emergency use authorization from the World Health Organization.

Sinopharm's two-dose COVID-19 vaccine was shown to have an efficacy rate of roughly 79% to protect against symptomatic and hospitalized infections. Controversy over the lack of published data about the vaccine has continued despite Sinopharm receiving emergency use authorization from the World Health Organization.


What our experts say

The World Health Organization granted emergency use to one of Sinopharm's vaccines in May 2021. The company has two COVID-19 vaccines, and both are made with an inactivated virus. The company's second vaccine has not yet been approved by the WHO.

Sinopharm's shot uses a coronavirus variant that scientists have deactivated by dousing it in a chemical in a lab. The process means it cannot harm the human body, but can help familiarize our bodies with the traits of SARS-CoV-2 so we mount an immune response if exposed.

To estimate how well the jab works, researchers studied people who a) got their shot at least two weeks prior and b) had their two shots spaced out by 21 days. Using those measurements they found Sinopharm's vaccine efficacy to be roughly 79% for protecting against symptomatic disease and hospitalization across all age groups in phase three clinical trials.

That said, few adults over 60 were involved in the trials. That means efficacy data was not estimated for the 60+ group. Because of this, the WHO is not recommending an upper age limit for the vaccine. Data suggests it is likely to still offer some protection in older people. The WHO is not recommending the vaccine for people younger than 18 years of age either, until further studies in this age group are completed.

Right now the WHO recommends a two dose regimen for the shot, with the injections 3-4 weeks apart.

Sinopharm's clinical trials enrolled roughly 40,000 participants across the United Arab Emirates, Bahrain, Jordan, and Egypt. So far regulators have approved (either formally or for emergency purposes) the vaccine in over 40 countries. Now that the WHO has granted emergency approval to the vaccine, it is also eligible to be purchased by the vaccine resource-sharing initiative COVAX.

The vaccine has relatively easy storage requirements, so it may be more useful in low-resource settings. It has a vial monitor that changes color when the vaccine is exposed to heat.

Little data about side effects is available. No data is available on the vaccine's ability to protect against transmission of COVID-19 and for this reason, preventive measures like hand washing, masking, and physical distancing are still important to implement.

Some controversy surrounds the Sinopharm vaccine. The head of the Chinese Center for Disease Control and Prevention stated that the efficacy of Chinese COVID-19 vaccines is "not high" despite promising clinical trial data. Sinopharm also has yet to publish full clinical trial results, so researchers fear a lack of transparency behind the data may lead to vaccine hesitancy.

Geopolitical challenges have also made some reluctant to trust state-owned pharmaceutical and biotechnology companies like Sinopharm. In many countries the only accessible vaccines are from China, leaving little choice for immunization options.

There were reports of wealthy people getting the vaccine to boost tourism in the United Arab Emirates. Another controversy also occurred in the country as Sinopharm planned to manufacture the vaccine under the name "Hayat-Vax" without releasing phase III clinical trial data.

Finally, political and business leaders in the Philippines and Japan got Sinopharm vaccines that were not legally imported.

Context and background

Sinopharm's inactivated vaccine has shown promising clinical trial data but one of the biggest challenges the company faces is its lack of published data. Following successful phase III clinical trials, it is customary for most groups to publish their findings in a peer-reviewed scientific journal or through their own procedures. This allows other scientists to scrutinize and review the findings, evaluate side effects, determine how safe and efficacious the vaccine is, and look for any inconsistent or missing data. Sinopharm has produced a study like this in The Lancet for its smaller phase I and II trials, but not for its phase III data. Before the WHO's recent emergency use authorization, most of the reports about the data's efficacy came from countries that ran the trials, along with press releases put out by Sinopharm. Until this data is published in a credible, rigorous journal, it is likely that questions about the vaccine's safety and transparency will continue.


  1. Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBIBP-CorV: a randomised, double-blind, placebo-controlled, phase 1/2 trial (The Lancet)
  2. The Sinopharm COVID-19 vaccine: What you need to know (World Health Organization)
  3. WHO lists additional COVID-19 vaccine for emergency use and issues interim policy recommendations (World Health Organization)
  4. China’s COVID vaccines are going global — but questions remain (Nature)
  5. Sinopharm (Beijing): BBIBP-CorV (COVID19 Vaccine Tracker)
  6. Sinopharm, Sinovac COVID-19 vaccine data show efficacy: WHO (Reuters)
  7. The UAE Covid vaccine could become a global leader, but we must see full data (The Guardian)
  8. Effectiveness of Chinese vaccines ‘not high’ and needs improvement, top health official says (Washington Post)
  9. How the Sinopharm Vaccine Works (New York Times)
  10. China gives its first COVID-19 vaccine approval to Sinopharm (Reuters)
  11. China's Sinopharm vaccine offered to elite few in UAE tourist deal (The Guardian)
  12. Coronavirus vaccine from China’s Sinopharm is 86% effective, UAE officials say (Washington Post)
  13. Philippine officials under fire from critics, health authorities for unsanctioned Covid-19 vaccinations (Straits Times)
  14. Chinese vaccines circulating under the surface From wealthy people to Nagata Town? Targeted Japanese market (Mainichi)
  15. Coronavirus: UAE authorises emergency use of vaccine for frontline workers (National News)
  16. Egypt to start receiving volunteers for COVID-19 vaccine trials (Egypt Independent)
  17. Bahrain approves Chinese coronavirus vaccine, after Peru suspends trial (CNN)

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