The primary individuals have begun to obtain vaccines within the UK and US as a part of mass vaccination campaigns to immunise individuals towards COVID-19. Pleasure is constructing – lastly, the tip of the coronavirus disaster is in sight.
Since early December, aged sufferers and well being staff in 50 hospitals throughout the UK have been given the vaccine developed by Pfizer and BioNTech. This vaccine has additionally been granted emergency use authorisation by the Meals and Drug Administration within the US and is at the moment being administered to the primary precedence teams.
The favored assumption is that the Pfizer/BioNTech vaccine and the others in growth will scale back severity of the illness, scale back transmission of the SARS-CoV-2 virus, present inhabitants immunity and get us again to the normality of the pre-COVID period.
Whereas scientists, together with myself, are very excited on the prospect of an efficient vaccine and the prospect of returning to normality, you will need to mood this enthusiasm with warning. A number of questions nonetheless stay about how a lot safety an efficient vaccine affords, to whom and for the way lengthy.
A bumper crop of vaccines
Beginning a mass vaccination programme is a crucial first step in the direction of ending this pandemic. And it has come comparatively rapidly. Producing an efficient vaccine towards an infectious illness is an extended course of that previously has often taken a few years.
The event of the COVID-19 vaccine this yr, however, has been terribly quick. It has proven how rapidly scientific growth might be achieved by way of collaborative onerous work, and the way a lot the need can produce the means. Throughout 2020, 61 vaccines have been developed, with a variety of these in scientific trials, and a few reporting a greater than 90% efficacy charge towards COVID-19. There isn’t any doubt that it has been a yr of outstanding progress.
However even when broadly used, the efficacy of vaccines has not traditionally been assured. Just one illness, smallpox, has ever been really eradicated – and reaching that took greater than 200 years. In the meantime, we proceed to stay with ailments akin to polio, tetanus, measles and tuberculosis, with the extensive use of vaccines serving to shield susceptible cohorts. So we don’t but know if immunisation will eliminate COVID-19 for good.
Studying from the roll-out
There are different questions for which we additionally want solutions.
The efficacy of the vaccine throughout a scientific trial is measured by what number of circumstances occurred within the vaccinated group. To establish the efficacy throughout the inhabitants, additional particulars are wanted on whether or not these circumstances are principally gentle or whether or not they embody vital numbers of average and extreme circumstances.
We additionally want readability on transmission – will the vaccine stop asymptomatic individuals or these with very gentle signs of COVID-19 from spreading the virus? The latest resurgence of the virus means that transmission of COVID-19 isn’t slowing down, and that we’d like a transmission-blocking vaccine to actually convey in regards to the finish of the pandemic. A severity-reducing vaccine will stop deaths and the overwhelming of hospitals, however not cease the unfold.
Whether or not the Pfizer/BioNTech vaccine or the opposite vaccines in late-stage trials can obtain that is troublesome to evaluate, as a result of this may require routinely testing all trial members in addition to their contacts – that is troublesome to do in such giant numbers. As an alternative, because the vaccines roll out within the UK and the US, the after-effects will likely be carefully watched and we are going to get a greater really feel of the general influence.
One other side that we have to perceive is how nicely the vaccine may go throughout completely different age, inhabitants and danger cohorts. Lastly, there’s the query of how lengthy immunity will final. Individuals should be watched and tracked three, six and 12 months after receiving the vaccine to evaluate the completely different ranges of protecting antibodies of their blood.
We are able to’t wait a yr to search out out the reply to all these questions. That is the place mathematical modelling of doable epidemic trajectories with completely different vaccination eventualities might be useful.
Mathematical modelling has been on the forefront of coverage decision-making worldwide all through the pandemic, because it permits us a strategy to assess the potential results of each non-pharmaceutical interventions – akin to lockdown or completely different check, hint and isolate methods – and pharmaceutical interventions akin to a vaccine or antiviral therapy.
Modelling can assist us discover what the impact of various ranges of vaccine efficacy and protection (proportion of individuals vaccinated) will likely be on the copy quantity R (which signifies the speed of transmission within the inhabitants) or on the variety of COVID-19 circumstances and deaths. We are able to additionally discover the potential variations between a vaccine that reduces severity, one which blocks transmission and one which does each. We are able to mannequin how these outcomes change if we mix completely different ranges of coronavirus restrictions with completely different vaccines.
Along with colleagues, I’m engaged on answering such questions and exploring whether or not vaccination towards COVID-19 will stave off third and subsequent waves.
For now, we’re nonetheless very early within the vaccination campaigns and we don’t but even have printed outcomes from our fashions. So sadly it’s nonetheless too troublesome to say whether or not life will return to regular subsequent yr.
The excellent news is that by combining the outcomes from the not too long ago began mass vaccination campaigns within the UK and the US with mathematical modelling, we are going to quickly have a number of the solutions we’d like.
We must always all be excited on the prospect of an efficient vaccine, however we also needs to be cautious of the truth that we aren’t there but. And till we get there, we have to observe the COVID-19 security measures to guard ourselves and others.
Jasmina Panovska-Griffiths doesn’t work for, seek the advice of, personal shares in or obtain funding from any firm or organisation that will profit from this text, and has disclosed no related affiliations past their educational appointment.