Vaccines for COVID-19 are now being introduced, but in some parts of the world this good news has been mitigated by the emergence of new, potentially more contagious strains of the virus. The exact course of the pandemic has become more uncertain.
Certainly, the next three or more months will be challenging, and a virus-free life is probably a long way off. Some things may not go back to what they were before.
It’s hard to predict how things will turn out, but there are some things we can predict with a relative degree of reliability. With that in mind, here’s what we can expect from next year.
What impact will the new strain have?
Currently, there is only limited information on the new virus strain. Although not yet confirmed, it appears to be more contagious but does not lead to more serious disease or may avoid the immunity derived from the vaccine.
However, the variant suggests that the virus is able to produce significant mutations, and further mutations may alter the course of the outbreak. Tackling the pandemic has therefore become an even more urgent task.
Tighter behavioral restrictions are likely to last until the new year, and we may need additional restrictions to control the virus if it is indeed more contagious.
How long until we see the effects of the vaccine?
Producing sufficient doses of vaccines is a big task – production could be a bottleneck. Even assuming we can do whatever we need, human immunization will take many months.
In the UK, GPs are throwing out vaccines, and the average English doctor cares for almost 9,000 people. Assuming GPs work eight hours a day, they need 10 minutes to vaccinate someone, and each patient needs two injections, it would take them more than a year to see all their patients. The others will, of course, help with the introduction, but this shows the size of the task. Delays will be inevitable.
In addition, two doses of Pfizer should be given 21 days apart, and full immunity comes seven days after the second injection. Other vaccines – such as AstraZeneca – require an even longer period between doses. It will take at least a month (if not more) to see the full effect of each vaccinated person.
In countries that have relaxed the rules of social distancing for Christmas, we could see a post-Christmas leap in cases. In this case, it is unlikely that vaccines will change much in the beginning – the disease will have too much momentum in early 2021. This will probably be the case in the UK thanks to a new strain of the virus, although restrictions have not been lifted for many. Public awareness of the spread of the disease is needed to avoid losing confidence in vaccination.
How will the pandemic unfold?
After people get over COVID-19 (or receive the vaccine), they become immune (at least in the short term). Those infected later then increasingly have contact with immune individuals rather than susceptible individuals. The transmission therefore falls and eventually the disease stops spreading – this is known as herd immunity.
The level of immunity in the population required to stop the spread of the virus is not precisely known. It is considered to be between 60% and 80%. We are nowhere near that at the moment – meaning billions around the world will need to be vaccinated to stop the spread of the virus.
This also relies on vaccines that prevent the transmission of the virus, which has not yet been proven. If so, we will see a decline in the number of COVID-19 cases, perhaps as early as spring 2021. However, blockades and other measures will still be needed to limit transmission while vaccination builds population immunity – especially where the more contagious strain of the virus has taken maha.
Conversely, if the vaccine only prevents infected people from becoming seriously ill, we will remain dependent on infections to build the herd’s immunity. In this scenario, vaccinating the vulnerable would reduce the mortality rate, but the serious illness and long-term COVID affecting younger people would likely continue.
What is likely to change?
Vaccines are not a silver bullet – a certain level of precaution will need to be maintained for months. In areas where a highly contagious strain is prevalent, high-level restrictions may last until the introduction of the vaccine is completed. All changes will happen slowly, primarily in the area of home visits and reopening of hospitals for regular treatment.
Over time, travel will become easier, although airlines may begin to require vaccination certificates. Although some countries require vaccination against yellow fever to enter, requiring immunity passports for COVID-19 is likely to prove controversial.
Wearing masks could become a social habit on a global scale, as is now the case in Asia – for example, when someone is not feeling well or is worried about their health.
Can vaccination lead to virus eradication? We do not yet know how long vaccine-based immunity lasts – and long-term immunity will be crucial. Complete eradication of the virus will be very difficult and will require a global effort.
Although we are close to eradicating polio, smallpox remains the only human disease we have completely eradicated, and it has lasted for almost 200 years. For example, measles, although almost eradicated in many countries, continues to return.
Some vaccines, such as measles, provide near-life protection, while others need to be repeated, such as tetanus. If COVID-19 mutates regularly and significantly – and its potential has just been shown – we may need to take new vaccines from time to time, as we do against the flu. In the long run, we should also vaccinate children to maintain herd immunity.
The social and economic effects of a pandemic are likely to be long-lasting as well. Maybe life will never go back to what it was before. But it is up to us to make it safer by better preparing for future pandemics.
Adam Kleczkowski, Professor of Mathematics and Statistics, Strathclyde University
This article was published in The Conversation magazine under a Creative Commons license. Read the original article.