2 in 1: Flu and Covid vaccine proves effective in the elderly, says study

Awaited for years by experts and health authorities, Moderna's multicomponent vaccine, which acts against Covid-19 and the flu, has proven to be superior to vaccines administered separately, according to data from a phase 3 clinical trial. Named mRNA-1083, it simplifies immunization against both viruses.

Recently published in the journal JAMA , the study states that mRNA-1083 demonstrated immunogenicity comparable to that of vaccines currently used against seasonal influenza (subtypes A/H1N1, A/H3N2, B/Victoria and B/Yamagata) and against the Omicron XBB.1.5 variant of SARS-CoV-2.

The new vaccine, developed with the same messenger RNA technology as the Covid vaccine approved during the pandemic , represents a promising advance in the fight against two respiratory diseases, especially among people aged 50 or over, who are more susceptible to complications.

The expectation surrounding the approval of the combined flu and COVID-19 vaccine revolves around the possibility of facilitating campaigns by combining protection in a single dose, with the potential to increase adherence among the elderly and make logistics more efficient.

Despite the good results, Moderna does not expect a quick approval from the United States Food and Drug Administration (FDA) for its vaccine, due to recent changes in regulatory policy implemented by the new Secretary of Health, known for his anti-vaccine positions.

How were the Moderna vaccine tested for immunogenicity and safety?

Funded by Moderna, the randomized clinical trial involved more than 8,000 adults aged 50 and older. Participants were randomly assigned to two groups: one received the combined vaccine and the other received the separate vaccines, with a placebo to simulate two doses.

The main objective of the study was to verify whether the combined vaccine induced a stronger immune response than current vaccines against influenza and the XBB.1.5 variant of COVID-19. To do this, the researchers performed a serological test, a blood test used to measure antibody production.

The results showed that antibody levels were between 20% and 40% higher among those who received the combined vaccine , compared to those who received the vaccines administered separately. The new vaccine produced a stronger immune response against Covid and several strains of the flu.

Former FDA chief scientist Jesse Goodman told NBC News that the data is promising and suggests that the combination vaccine may offer equal or better protection than traditional vaccines. He said antibody levels correlate with the degree of protection the vaccine provides.

Although side effects such as fever and chills were more frequent among those who received the new vaccine, this may be attributed to the simultaneous activation of the immune system against two different viruses, which generates a more intense, although expected, inflammatory response.

Political-ideological problems in releasing Moderna's new vaccine

In an attempt to launch its combination vaccine as early as this fall, Moderna plans to use the latest data to apply for FDA approval. However, the company does not expect regulatory approval until 2026, due to the need for more data on its effectiveness against influenza.

It’s not yet clear whether the FDA’s new rule requiring placebo-controlled clinical trials to approve new vaccines will apply to the combination shot. The agency has already imposed similar requirements on Novavax and may do the same for updated shots from Pfizer and Moderna.

According to Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children's Hospital, mRNA vaccines have become a favorite target of anti-vaccine movements in the US, with state laws seeking to restrict their use.

For Jesse Goodman, a combined mRNA-based vaccine would also represent a strategic advance, by allowing faster responses to future flu pandemics, overcoming the current production process, which still depends on growing viruses in eggs.

It is important to note that the study did not directly assess the clinical efficacy of the vaccine , that is, how many vaccinated people became ill or not. Although it generated a superior immune response to traditional vaccines, real protection still needs to be confirmed.

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