Form of words:
New Delhi: According to researchers from the University of Oxford in the UK, COVID vaccines reduce the transmission of the virus in addition to providing protection against infection.
However, the effect on transmission of the delta variant decreases three months after the second dose for the two vaccines studied — by Pfizer and Oxford-AstraZeneca, the researchers said. The lack of protection against transmission, he said, was more pronounced in the case of the latter vaccine, which is manufactured and marketed in India as Covishield.
In one discovery, which is yet to be peer reviewed, the researchers found that the likelihood of transmission from vaccinated individuals was low for both the alpha and delta forms. However, he said, the latter erodes some of the protection associated with the vaccine against transmission.
This may be because the delta variant makes infection more common, increasing the chances of transmission from vaccinated individuals who are known to be infected, he said.
The study may also explain why the delta variant is increasing the number of COVID cases even among populations with high vaccine coverage.
For the research, the study authors used large-scale contact tracing data of more than 1,39,164 people in the UK.
found that both the Pfizer-BioNTech mRNA vaccine and ChAdOx1 developed by Oxford University and British-Swedish firm AstraZeneca reduce the transmission of SARS-CoV-2 from infected individuals.
Read also: Merck COVID pill raises new hope of reducing hospitalization and death by 50%
‘Pfizer provides better protection against transmission’
it had been imagine it Earlier vaccines reduce viral loads, and since higher viral loads are associated with higher transmission, vaccination will also reduce transmission.
However, the Oxford researchers pointed out that while vaccination allows the rapid elimination of viable infectious virus, it leaves behind damaged ineffective viral particles that are still detected by COVID tests.
He further noted that fully vaccinated individuals infected with the Delta variant who received the Pfizer vaccine were less likely to have further spread of the virus than those who received the AstraZeneca-Oxford vaccine.
The team also observed that this protection against further transmission decreased three months after the second dose for both vaccines.
Even after the protection is reduced, this is still enough to sabotage the transmission of the Alpha version. However, the protection is significantly reduced in the case of the Delta variant, especially for the Coveshield.
Three months after the second dose of Covishield, there was no difference in transmission of the delta variant between vaccinated and non-vaccinated individuals, the researchers said.
This lack of protective behavior over time could be a factor in less social distancing and mask-wearing over time, he said.
However, since studies have shown that antibody levels decrease over time in vaccinated individuals, there may also be biological explanations for this decreased protection.
The authors suggest that ultimately, booster vaccination may help control transmission as well as prevent infection.
(Edited by Rachel John)
Read also: Talking about COVID booster shots is not fair, studies show antibodies in last one year: ICMR chief
subscribe our channel youtube And Wire
Why is the news media in crisis and how can you fix it?
India needs free, unbiased, non-hyphenated and questionable journalism even more as it is facing many crises.
But the news media itself is in trouble. There have been brutal layoffs and pay-cuts. The best of journalism are shrinking, yielding to raw prime-time spectacle.
ThePrint has the best young journalists, columnists and editors to work for it. Smart and thinking people like you will have to pay a price to maintain this quality of journalism. Whether you live in India or abroad, you can Here.