Strange case of Russia’s Sputnik 5 Covid-19 vaccine

Strange case of Russia’s Sputnik 5 Covid-19 vaccine

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“…maybe sometimes it’s riskier not to take a risk.” ― Danny Wallace

Sputnik 5 is anything but a medical coup.

It is a propaganda coup; a political coup; a marketing coup – it secured orders for one billion doses of the yet unproven vaccine from 20 countries. Because the world knows that global capacity is to produce 2-4 billion doses of the Covid-19 vaccine by the end of 2021, and therefore much of the 7.8 billion global population will remain without a vaccine for a long time. And no country wishes to be left with an unprotected population. Hence the rush to place orders for any potential vaccine.

Sputnik 5 is a potential but as yet unproven vaccine.

How Effective is Sputnik 5?

No one knows.

  • It was tested on only 76 people: 38 in Phase I and 38 in Phase II trials. Both trials were in Moscow. This number is too small to arrive at any conclusion. Oxford vaccine trial, for example, had 1,077 people.
  • Sputnik 5 is a two-dose vaccine, the second dose is given 21 days after the first dose. But in Phase I/II trials, only one dose was given.
  • Its Phase I and II trial results are not published and therefore not peer-reviewed.

For these reasons, Phase I/II trials are inadequate to prove vaccine’s efficacy and safety.

Normal practice is to license a vaccine for public use only after completion of Phase III trials.

Sputnik 5 Phase III Trials

Sputnik 5 Phase III trials were to start on 12 August on 2000 people in Russia, the UAE, Saudi Arabia, Brazil and Mexico. The number of people in the trial is small. In the eight vaccines already in Phase III trials, one has 10,000 people, the remaining seven have 30,000-60,000 people.

Completion date of Sputnik 5 Phase III trials is not known. Usually, completion dates are one year after the outcome of the last dose given is known. Oxford vaccine trial started in April. Its listed completion date is May 2021. For BNT/Pfizer and NIH/Moderna trials primary completion dates are registered as mid-2021, and final completion estimated date is late 2022.

But trials are often delayed because volunteers have to be found and screened. Because of exclusion clauses of the trials, many volunteers are screened out. For the already planned trials, 250,000 volunteers are required and the number may soon touch 500,000. Such large number of volunteers are not easy to find.

CanSino’s Phase 1 trial in Canada hasn’t begun because China government has not released shipment of vaccine.

Oxford/AstraZeneca vaccine’s 30,000-person Phase III trial was to begin the US in July but hasn’t yet started; and completion date for its Phase III trial in Brazil is delayed by several months.

It is fair to estimate that Sputnik 5 Phase III trial will be completed only by mid to late 2021. Only then will its efficacy and safety be known.

What Is The Measure of Efficacy?

In the US, Federal Drug Administration (FDA), which approves the vaccines for public use, requires that the vaccine prevent the disease or decrease its symptoms in at least 50 percent of those who receive it. For example, flu vaccine does that in 40 to 60 percent of the people.

We do not know what effectiveness criteria Russia uses. But Sputnik 5 was tested on so few people that it could not have proved that it met these criteria.

What Are The Side Effects of Covid 19 Vaccines?

In the vaccines presently undergoing trials, 4% to 40% of the vaccinated people had mild fever. Fatigue, headache, and local tenderness were the other common side effects. But these were tolerable and mostly ameliorated by paracetamol. Other side effects will be known only after completion of Phase III trials.

Uncommon or rare, and long term, adverse effects, and effect on groups of people who were either not represented in the trials or were not represented in sufficiently large number, will be known during and after Phase IV trials. These trials will also tell us how long the effect of the vaccine lasts.

What Does Sputnik 5 Registration Mean

Sputnik 5 ‘registration’ authorises only restricted use on selected group of people during 2020. Public use may be authorized in 2021.

Sputnik 5 was not the first vaccine to be authorised such limited use. On 29 June 2020, China authorised similar restricted use of CanSino’s Covid 19 vaccine in its military.

How Many years It Takes For A Vaccine To Be Approved?

Because companies were reluctant to invest in vaccines because of low profit margins and fear that the disease may subside before the vaccine was approved, it took many years to license a vaccine for public use. The mumps vaccine was the fastest to move, in four years, from scientific concept to approval in 1967. Chickenpox vaccine took 34 years. And even after 36 years of trying, an HIV vaccine is yet to be found.

Now governments are taking the financial risk and investing heavily in developing Covid 19 vaccines that may not work. And advancements in science and technology have given researchers new tools to speed up the development of vaccines. Approval in shorter timeframe is therefore possible.

In January, the US decided to develop a Covid 19 vaccine in 12-18 months and has invested  US $9.5 billion to speed up development and jump-start manufacturing before research is finished. US, UK, Europe have ordered 1.5 billion doses of vaccines which are still undergoing trials. It is hoped that a Covid 19 vaccine will be approved for public use by early or mid-2021.

How Many Covid-19 Vaccines Are Under development?

At present, 196 vaccines are in various stages of trial: 170 animals and labs, 15 Phase I, 03 Phase II, and 08 Phase III. How many of these will emerge successful is difficult to forecast.

Conclusion

Covid 19 pandemic is raging, even escalating. That puts pressure on countries to rush for a vaccine. Under such pressure countries may authorize emergency use of a vaccine on specified groups without waiting for the completion of Phase III trials. That is without fully establishing the efficacy and safety of the vaccine. This is more likely to happen if the Phase I and II trials data is satisfactory, even if not impressive, and even if the scale of the trials was small. This has happened to Russia’s Sputnik 5 and China’s CanSino vaccine.

That India and 20 other countries are interested in participating in Sputnik 5 Phase III trials and in making the vaccine is a proof that countries may give the go-by to safety precautions in the haste to get a Covid 19 vaccine.

“The reward is in the risk.” ? Rachel Cohn

DISCLAIMER : Views expressed above are the author’s own.



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