COVID vaccines and what they mean for senior communities - Part 1
Vaccination is an important tool to fight communicable diseases. In December, the US authorized the distribution of the first COVID-19 vaccines, a long-awaited decision that established hope that the pandemic will soon be under control and lives will go back to a more familiar "normal" soon. But what do we know about the currently available COVID-19 vaccines and when can senior communities hope to go back to normal? Prof. Martin Hibberd, Professor of Emerging Infectious Disease, London School of Hygiene and Tropical Medicine, sat down with Enviral Tech on December 21 to answer 12 of the most pressing questions about the COVID-19 vaccines and what they mean for the senior care community.
This interview has been edited for brevity and clarity.
Enviral Tech: In long-term and senior care communities, who do you think should be vaccinated first?
Pr. Martin Hibberd: “It is quite clear that the residents should have the vaccine first because they are the people vulnerable to getting the disease. The care workers should also get vaccinated in order to reduce the chance of transmission, but we don't yet know whether the vaccine will actually do that. We assume that it will reduce the transmissibility of the virus, but it may not do it completely. So, actually, for the care workers, the most important thing is to continue testing.”
Senior care residents should get the COVID vaccine first.
If only one of the residents in a shared room gets the COVID-19 vaccine, is their roommate protected?
Unfortunately non-vaccinated residents are not really protected even if their roommate was vaccinated. The level of protection against COVID-19 for the non-vaccinated residents depends on who else they are meeting. If they are only in contact with their vaccinated roommate, it might help a little bit, but we don't yet know whether the vaccine will prevent you from carrying the virus. So even though you are vaccinated, most likely you are protected against the disease [symptoms], but you may not be protected against carrying the virus itself. So you might still transmit to somebody else and they might suffer the disease.
What is the likelihood of the current COVID-19 vaccines reducing transmission?
They probably do reduce transmission, but they don't prevent it completely. We know that during the pre-symptomatic phase, relatively small doses of the virus can still lead to transmission of COVID-19. So we expect the vaccine to reduce the viremia [presence of the virus in the blood], but probably not eradicate the whole transmission process.
Are we aiming for herd immunity for the COVID-19 vaccines? If so, what is the optimal number of people who should get vaccinated in order to establish herd immunity in a senior community?
The point of herd immunity is to reduce the number of daily infections. Getting 60% of the population vaccinated is usually the minimum, but normally we target at least 70% and you hope for 80%. That number depends on how effective the virus is. So for some viruses, 60% is sufficient, but for others you have to get right up to 90%-95%. But it does not mean that as soon as you vaccinate 80% of the people, you are safe. You have to wait until the number of infected people has dropped, hopefully to near zero. So it will take a little while after vaccination [before we can go back to normal]. We just learned about this new strain of the COVID-19 virus in the UK, that is perhaps a little bit more effective. So the number of people who we think need to get vaccinated might change over time. The only people who are protected from disease are those who got the vaccine. My guess, and it is only a guess until we start seeing those numbers, is that for COVID-19 the number of people who need to get vaccinated is probably around 70%-75% at the moment.
" It does not mean that as soon as you vaccinate 80% of the people, you are safe."
Once enough people are vaccinated, can we reduce the COVID-19 surveillance effort and rely on vaccination and previous infection control procedures to keep seniors safe?
I think we need to do just as much surveillance as we are right now, maybe even more. I am all in favor of regular testing. I think senior facilities are the ones that should be getting regular testing. That allows those communities to open up and feel safe inside. The vaccine may not be sufficient until every single resident has been vaccinated. You still need to do testing on people entering the buildings because even if they have been vaccinated, they might still carry the virus and be able to transmit it.
Martin Hibberd is a Professor of Emerging Infectious Diseases in the department of Pathogen Molecular Biology, at the London School Of Hygiene & Tropical Medicine. He is also a leading expert in the UK Public Health Rapid Support Team, and Associate Director and Senior Group Leader for the Infectious Disease group at the Genome Institute of Singapore. Pr. Hibberd also has adjunct positions at the National University of Singapore School of Public health and at the Sanger Genome Institute.