Demand for flu vaccine soars as countries plan for second Covid-19 wave
Officials in the UK are considering whether to offer flu shots to everyone
The possible beneficial adjuvant effect of influenza vaccine to minimize the severity of COVID-19
Resultant immunity against prior influenza infection would, at least in part, foster immunity against SARS-CoV-2.
Public Health England
It is more important than ever that we have effective plans in place for the 2020/21 flu season to protect those at risk, prevent ill-health and minimise further impact on the NHS and social care
The Dual Epidemics of COVID-19 and Influenza (JAMA 11 June)
Likelihood of co-epidemics of COVID-19 and influenza
Considerable morbidity and mortality
Stressing the health system
2018 – 2019 flu session, US
35.5 million influenza cases
490 600 hospitalizations
34 200 deaths related to influenza
Vaccination prevented
4.4 million influenza cases
58 000 hospitalizations
3500 deaths
Seasonal influenza vaccines have variable year-to-year effectiveness
Can significantly reduce morbidity and mortality, especially with high coverage
Advocates mass flu vaccination
BUT
Increased Risk of Noninfluenza Respiratory Virus Infections Associated With Receipt of Inactivated Influenza Vaccine (Clinical Infective Diseases, 2012)
Influenza vaccination is effective in preventing influenza virus infection and associated morbidity among school-aged children
Randomized placebo-controlled trial of influenza vaccination
115 participants were followed up for 272 days
Flu vac group had higher risk of Acute Respiratory Infections associated with confirmed noninfluenza respiratory virus infection
RR, 4.40
The majority of the noninfluenza respiratory virus detections were rhinoviruses and coxsackie, echoviruses, and coronavirus 229E
Receipt of flu vac could increase influenza immunity at the expense of reduced immunity to noninfluenza respiratory viruses, by some unknown biological mechanism.
Temporary nonspecific immunity leading to interference between epidemics of respiratory viruses could have important implications
The UK’s public health response to covid-19
Possible correlation between influenza vaccination and COVID-19 deaths rates in European countries
Flu shots and the risk of coronavirus infections
Possibility that seasonal flu shots are potential contributors COVID-19
Flu shots increased fivefold the risk of acute respiratory infections caused by a group of noninfluenza viruses, including coronaviruses
Odds ratio of 4.91
Influenza vaccines may alter our immune systems non-specifically to increase susceptibility to other infections