Episode #34 - Vaccines, variants & mass gatherings 

16 April 2021 | Science conversation

Vismita Gupta-Smith

Hello and welcome to Science in 5. I’m Vismita Gupta-Smith and we are talking about vaccines, variants and mass gatherings today. WHO's Chief Scientist, Dr. Soumya Swaminathan, will be talking to us about these issues. Welcome, Soumya.

Dr. Soumya Swaminathan

Hello, Vismita. Nice to be back doing Science in 5.

Vismita Gupta-Smith

What do we know today about how much protection these vaccines are giving us?

Dr. Soumya Swaminathan

What's really important is that almost all of these vaccines are highly protective against severe disease, which leads very often to hospitalisation and then unfortunately to death. So, while they may not completely prevent infection, the immunity that the body develops in response to vaccination, is good enough to protect people from getting sick even if they get the infection. We're also learning about protection against infection, because this is something that wasn't clear from the trials. But in countries like Israel and the UK, which have been studying it very systematically, it appears that people who have received the first dose have about 70 to 80 percent protection against infection. And after the second dose, this could be even higher. Now, this may vary from vaccine to vaccine, so we cannot generalise. We need to collect more data. I think what's important to remember is that even as one gets vaccinated, we have to maintain all the other precautions and take all the other public health measures that WHO has been advocating, because each of these tools actually adds a layer of protection.

Vismita Gupta-Smith

Soumya, with these variants out there, how much protection are these vaccines providing and will people need booster shots to protect against these variants.  

Dr. Soumya Swaminathan

What has been shown so far is that if a person receives a full course of vaccination, then there's enough protective immunity in the body to protect against severe disease, even from these variants. So, even in the countries where there are a lot of variants circulating, people who have been vaccinated are not ending up in hospital or dying even if they do get the infection. So, I think overall the news is positive. Companies and labs around the world are working on newer versions of the vaccine, which accommodate the proteins of the variant virus. So, I think in the next few months, we will begin to see results from clinical trials which are looking at these new modified vaccines. And then we will be able to take a decision on whether people are going to need boosters or not.

Vismita Gupta-Smith

Soumya, we are seeing that people are tired. It's been long periods of isolation and being locked up in your homes. And so, there are these gatherings that are happening, whether they're smaller family gatherings or bigger gatherings, mass gatherings. What does our evidence and data say about what happens to COVID-19 transmission when we gather and not observe the public health precautions? 

Dr. Soumya Swaminathan

So, we've known for quite some time now about how this virus spreads and what it likes. It likes close contact between people. It likes crowded environments, and it likes close settings, indoor settings with poor ventilation so that it can spread most efficiently from person to person. We also know that many of the variants that are circulating now, particularly the variants of concern, are much more efficient, one and a half to two times more efficient at spreading. So, the virus has got smarter at spreading, it's just looking for opportunities. We know mass gatherings, whether they are, you know, gatherings for weddings or parties and pubs or whether they are sporting events or religious events, that all of these have the potential to become mass spreading events. And we know from many documented research studies done last year that mass gatherings did result in a huge increase in infections, which are usually seen a couple of weeks later. So knowing all of this, I think it's really important we understand that people are tired and, you know, they want to get back to normal life. But this is not the time to relax at all because the vaccination programs in most countries have not even begun to approach the levels of herd immunity that we need. And so, we need to recognise, people need to recognise that engaging in these kind of activities where we are gathering without any precautions is endangering not only themselves, but the lives of their loved ones and friends, and particularly the older people and the vulnerable people in the community.

Vismita Gupta-Smith

Thank you, Soumya. That was Science in 5 today. Until next time, then. Stay safe, stay healthy and stick with science.