Written by Dr Tim Trodd
It is becoming clear that the Covid-19 virus will continue to circulate amongst humanity. Therefore, as we have discussed elsewhere, a Zero Covid strategy is not sustainable in the long term. We must assume, and plan for, the scenario where all humans will be exposed to the Covid-19 virus sooner or later. In countries with access to vaccines, the choice is whether to be exposed to the virus having been vaccinated or not vaccinated.
The choice for the over 60’s is clear, the benefits of the vaccine far outweigh the downside, particularly for those with chronic diseases. Here in Hong Kong, where there is ready access to an excellent vaccine, it is perplexing that 95% of the elderly in care homes have not been vaccinated.
For younger age groups (vaccines are now offered from the age of 12 upwards), there are different motivations for vaccination because the illness itself is generally mild. We may wish to travel easily with less quarantine, not spread the virus to the vulnerable or help society to achieve herd immunity. Another consideration is the prevention of Long Covid, a potentially disabling condition that affects at least 10% of young Covid patients. If the vaccine is generally well-tolerated in younger age groups then prevention of Long Covid alone would be worth the vaccination.
Does Vaccination Prevent Long Covid?
Several studies have shown that at least 10% of patients with Covid, even if mild, will develop symptoms of Long Covid. The vaccine side effects, on the other hand, are generally mild and transient. One rare side effect, Myocarditis, occurs at around 1 in 100,000 doses, but Myocarditis is also often found in patients with Long Covid, note the frequency of chest pain in the chart below. At this stage, we are still gathering evidence but it is likely that Long Covid is less frequent in those who come into contact with Covid-19 having been fully vaccinated. A recent study in the UK found:
“The King’s College London/ZOE app collaboration is the largest longitudinal study of Covid symptoms in the world. Through our work, we have also examined the impact of vaccines on existing Covid-19 symptoms and the chance of developing Long Covid. While it is now widely known that double vaccination reduces the chance of getting infected by around 85 per cent, our work indicates that on top of this, vaccines also decrease the likelihood, if someone does get infected, of developing Long Covid by up to 30 per cent”.
So a vaccinated person is 85% less likely to get infected, and if they do get infected then they are 30% less likely to develop Long Covid.
It is now accepted that those who have had Covid and recovered should be fully vaccinated. But what about those who have Long Covid? One study has found that there may be an overall benefit from vaccination in this group. The patients started with a typical range of symptoms as in the chart below:
Although some patients’ symptoms worsened the trend was to benefit from the vaccination:
So, it is likely that Covid vaccination, as well as preventing Covid infections, also decreases the rate of Long Covid in those that do get infected. The risk to benefit ratio in younger age groups is in favour of the vaccination, particularly taking into account that a Zero Covid policy is not sustainable. Having previously had a Covid infection, even if there are persistent symptoms of Long Covid, is not a barrier to vaccination.
1. Centers for Disease Control and Prevention. (2020, July 30). Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network - United States, March–June 2020. Centers for Disease Control and Prevention. https://www.cdc.gov/mmwr/volumes/69/wr/mm6930e1.htm.
2. Jacobson, K. B., Rao, M., Bonilla, H., Subramanian, A., Hack, I., Madrigal, M., Singh, U., Jagannathan, P., & Grant, P. (2021, February 6). Patients With Uncomplicated Coronavirus Disease 2019 (COVID-19) Have Long-Term Persistent Symptoms and Functional Impairment Similar to Patients with Severe COVID-19: A Cautionary Tale During a Global Pandemic. OUP Academic. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab103/6129932?guestAccessKey=39d1c850-0ae9-469e-9f21-5b7b2c3e6b5e+%0D%0D.
3. Tabacof, L., Tosto-Mancuso, J., Wood, J., Cortes, M., Kontorovich, A., McCarthy, D., Rizk, D., Mohammadi, N., Breyman, E., Nasr, L., Kellner, C., & Putrino, D. (2020, January 1). Post-acute COVID-19 syndrome negatively impacts health and wellbeing despite less severe acute infection. medRxiv. https://www.medrxiv.org/content/10.1101/2020.11.04.20226126v1.
4. Brianna Miller Daniel Sleat, Multiple Authors. The Hidden Pandemic: Long Covid. Institute for Global Change. https://institute.global/policy/hidden-pandemic-long-covid.
5. World Health Organization. (n.d.). Coronavirus disease (COVID-19): Vaccines. World Health Organization. https://www.who.int/news-room/q-a-detail/coronavirus-disease-(covid-19)-vaccines?topicsurvey=v8kj13%29&gclid=EAIaIQobChMIyOemkZLf8QIV0UNgCh1dYgXOEAAYAiAAEgL5fvD_BwE.
6. Centers for Disease Control and Prevention. (n.d.). Frequently Asked Questions about COVID-19 Vaccination. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/faq.html.
7. Strain, W. D., Sherwood, O., Banerjee, A., van der Togt, V., Hishmeh, L., & Rossman, J. (2021, June 17). The Impact of COVID Vaccination on Symptoms of Long COVID. An International Survey of People with Lived Experience of Long COVID. SSRN. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3868856.