According to the first clinical trial that examined co-administration of flu shots, flu jabs can be administered at the same time as AstraZeneca Covid or Pfizer vaccines.
The study revealed that while some people had more side effects from certain flu/Covid shots combinations, most were mild to moderate. Side effects that were most common included pain at the injection site, temporary fatigue, headaches and muscle pain.
The immune responses to the Covid or flu vaccines were not affected by the shot sequence. However, the FluBlok vaccine from Sanofi was found to be more effective when administered in conjunction with the Pfizer jab.
The findings of the Combining Influenza and Covid-19 Vaccination Study (ComFluCov), according to researchers, support the recent recommendation by the Joint Committee on Vaccination and Immunisation to offer Covid boosters in conjunction with flu jabs this fall and winter where practical.
The trial's lead scientist, Dr Rajeka Lazarus (a consultant in infectious disease and microbiology at University Hospitals Bristol, Weston NHS Foundation Trust), said that the preliminary results were very encouraging and could result in fewer flu shots and boosters.
She said that we don't expect booster doses to have an effect on the effectiveness of the Covid vaccine. The JCVI's advice comes amid fears that the next flu season will be worse than previous years, as people's immunity to influenza may have waned.
The trial was conducted at 12 NHS sites across England and Wales to examine side effects and immune responses after 679 people received their second shot of AstraZeneca or Pfizer Covid in one arm and one of the three flu vaccines the other.
The volunteers were split into two age groups: the 65-year-olds and the under-65s. They received either a Covid and flu shot or a Covid and placebo at their first appointment. FluAd was administered by Seqirus in UK to the older group, while Flublok, Sanofi, or Flucelvax were given to the younger group.
The participants were given either a placebo shot, or the flu vaccine three to four weeks later. This depends on what they missed at their first appointment. The volunteers returned to the clinic two to three weeks later to discuss side effects and take a blood sample.
Three quarters of volunteers experienced at least one side-effect systemic, including fatigue. This was regardless of whether the Covid shot was taken alone or with flu shots. One person was admitted to hospital for severe reactions.
97% of volunteers answered a question at the end of study and said that they would be happy to receive two vaccines at one time in the future. Although co-administration of Covid boosters or flu shots is a challenge for GPs Dr Lazarus stated that it is not uncommon to have more than one vaccine, especially in childhood. The Lancet magazine will publish the results.
