Covid-19: what you need to know today
The U.S. Food and Drug Administration’s endorsement of the safety and efficacy of the Moderna vaccine on Tuesday (regulatory clearance is expected by Friday) came with a bonus: details, previously unknown, that indicated the ability of the vaccine to prevent or at least reduce the transmission of Covid-19. As this columnist has previously written, what most of the Phase 3 clinical trials of Covid-19 vaccines sought to measure as a result was effectiveness in preventing infections. The vaccines developed by Moderna, Pfizer / BioNTech, Astra Zeneca / Oxford and the Gamaleya Institute have been shown to be effective, albeit to varying degrees, although all exceed the 50% mark set by the US regulator.
Based on the trial data published in the public domain, only AstraZeneca appeared to have tested the impact of the vaccine on transmission (it found that the vaccine reduced transmission), although this nugget was almost immediately forgotten in criticism that was directed at justified and understandable to vaccine developers to obtain data based on what was clearly a combination of phase 3 clinical trials. This is likely the reason the vaccine will not be approved in the US Based on these essays; An approval is expected in the UK, one of the locations where the Phase 3 trials were carried out, in a few days.
Also Read: Safe Covaxin From Bharat Biotech, Says Phase 1 Trial Data
Now, the FDA’s in-depth report on the Moderna vaccine candidate publishes data that was absent in the company’s initial data released in mid-November. According to this report, the company presented data showing that the first injection of its two-dose vaccine actually managed to reduce asymptomatic infections, something that could, if established through further research, mean that it reduces the transmission of the viral disease.
Vaccines that not only prevent infections, but also reduce or stop transmission, could effectively crush the pandemic and mean a faster return to normalcy. For example, it could mean that vaccinated people no longer have to wear masks because they cannot be transmitters.
Similar data are not available for the Pfizer / BioNTech vaccine, which is currently administered in both the US and UK, although the company is believed to be working on this.
While the Pfizer vaccine awaits regulatory approval in India, it is likely that the majority of Indians will not receive it. A vaccine control panel maintained by UNICEF puts the number of vaccine doses for which India has reached agreements with companies at 200 million, which is probably more accurate than the number of 1.6 billion in circulation. Of this, 100 million doses (of Covishield, the two-dose AstraZeneca / Oxford vaccine) are through an agreement between Gavi, The Vaccine Alliance and the Serum Institute of India (SII), which manufactures the drugs locally, and another 100 million, through an agreement between Gamaleya and Hetero Drugs. The Indian government is not party to any of the deals, although there seems to be a tacit understanding that the government, pending approval of the vaccine in India, will acquire most of the IBS production that has yet to be spoken.
India is also likely betting on Covaxin, the vaccine being developed by Bharat Biotech in partnership with the Indian Council for Medical Research. Phase 3 trials of Covaxin (also a two-dose vaccine) are currently ongoing and interim results are expected by the end of the year. Bharat Biotech has sought emergency use approval based on data from its phase 1/2 trials (this has yet to be released), but India’s drug regulator has rightly asked the company to return. with data from their phase 3 trials. Again, although there is no formal agreement (or has been publicized), the understanding appears to be that pending approval, the government will acquire much of the production from Bharat Biotech.
IBS is conducting its own phase 3 Covishield trials in India, and when those data are released it will be interesting to see if there is any indication that the vaccine prevents transmission, as the interim analysis of their trial data suggests. phase 3 that was released last month.