University of Hull virologist answers biggest COVID-19 vaccine questions

Dr Cheryl Walter is a University of Hull Virologist with more than 15 years of experience working on a variety of viruses and virus-host systems.

She graduated with a PhD in Microbiology from Rhodes University in South Africa in 2008, and continued her research at the University of Leeds where she first worked on bunyavirus gene regulation and later on hepatitis C virus-host interactions.

Dr Walter has continued her research at the University of Hull with a continued interest in virus-host interactions, using both model bunyaviruses and emerging flaviviruses systems.

She has extensive teaching experience both at undergraduate and postgraduate levels of study.

Here, Dr Walter answers some of the biggest current questions surrounding COVID-19 vaccines.

Dr Cheryl Walter
Dr Cheryl Walter

How pleased are you with the results of the vaccine trials?

Very pleased. Better than expected in terms of percentage protection and also more than one vaccine and more than one type of vaccine available. This really gives us many vaccination options, and more quickly than what we were expecting.

What will this mean in our battle to deal with Covid-19?

A vaccine is one of the most important tools in infection control. This will prevent people who take it from getting ill in the vast majority of cases and greatly reduce the number of cases in our population. This in turn will mean there will be less restrictions in place and far less disruption in society.

How do the three vaccines - Oxford AstraZeneca Pfizer and Moderna - differ and is any one better than the other?

The Pfizer and Moderna vaccines are very, very similar. They offer very similar rates of protection. One difference is that the Moderna vaccine is slightly easier to transport and store. The Oxford vaccine is developed using a different platform but sends the same coronavirus message to our immune systems to generate antibodies. This is even easier than the first two vaccines to store and transport and offers similar rates of antibody protection.

How safe are the vaccines?

Very safe! Vaccines have always been the best approach at preventing disease. As with any medication, there is a minute risk of complications but the technology used to develop these vaccines makes them very safe to use and also safe to administer the vast majority of the population.

Should we be concerned they have been produced, trialled and tested so quickly?

No, these vaccines are built on existing, tested technologies and have also still had to jump through all the safety loops. They have been developed so quickly because of the gargantuan multi-national effort by various scientists and pharmaceutical industries and have had huge financial investment. The role of these vaccines is been expedited by emergency FDA authorization. The only thing we don’t know about them is how long they will confer that immune memory.

How long will the vaccines protect us for?

That is something we are unsure of yet but based on the levels of antibodies in people vaccinated in the trials, there is a specific, high level antibody response that will be monitored over the months and probably years, so we continue to learn from the trials.

Can vaccines prevent transmission as well as deal with the symptoms?

Yes, they do. In the vast majority of cases, people will not get sick to start with and in a very small number of cases, they might get a very mild case of COVID-19, but still might not be very infectious.

What will be the process for vaccination i.e. how many doses, will it be injections, etc?

It appears that all three of the successful vaccinations will require an initial injection followed by a booster a month or so apart.

What are the side effects?

Side effects happen very seldom and are very similar to those listed for the annual flu jab. These include local swelling and tenderness at the infection site, a fever that self resolves in less than a day, aches and fatigue. These symptoms occur in a small minority of people and do not mean you are infected. It is still possible to become naturally infected from someone else a few days around the time you get vaccinated and so if these symptoms don’t resolve within a day or two of getting vaccinated, you should still get tested.

Is the vaccine unsafe for anyone such as pregnant women, those with certain underlying conditions, etc.?

For the vast majority of individuals, it is effective to take. It might not be possible for people who are sever immunocompromised to take it with the main reason being that the vaccine might not work in these people. These individuals should ask for more details from their doctor. Pregnant women are not normally included in a clinical trial group so more data will be collected on this group, but again, there is no risk of infection and it is unlikely to elicit serious side effects in this group. Doctors will look at the information continuing to come out of the trials and base their decisions on this and individual risk assessments for their patients.

Are you concerned anti-vaxx rhetoric and conspiracy theories will put people off?

Yes! Vaccines, even the very first ones have always been much safer to take than risk contracting an infectious disease. An enormous amount of damage was done when a handful of now discredited scientists created doubt almost 20 years ago now about the MMR vaccine. We are still suffering from that damage to this day. Those findings have been discredited over and over again, and it is the role of scientist and doctors to continue to advocate for vaccines and dispel incorrect evidence and theories in a transparent and accessible way to the public.

Many people remain hesitant. Can you understand their concerns and what would you say to them?

Yes, I can understand we’re still struggling with the after effects of the MMR controversy, and again that these vaccines have been produced so quickly. It is good that people question medical advances and seek information from reliable, medically or scientifically vetted sources yet also trust that doctors will always offer the best options for their patients.

Are you concerned by the logistics in delivering the vaccines?

No, I think it is more challenging than before but there are many companies already gearing up for transporting the more sensitive vaccines in an efficient and scaled up way. As these vaccines are getting developed, more work is also going on to ensure that they can safely reach all corners of the globe.

Who will be prioritised for the vaccine?

One of the many things that we have learnt from this outbreak, is that there are distinctly more vulnerable groups of people than others. These include the elderly, BAME group individuals and those with some chronic conditions. These individuals along with those that work in care homes in the NHS will be prioritised for the vaccine first, with other groups than vaccinated in stages, depending on their risk rating.

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