No vaccine contains strains of both the flu and the virus that causes COVID-19; COVID-19 is not the flu

The U.S. CDC encourages the use of a “[COVID-19] flu shot” on children.
Factually Inaccurate: In spite of the claim, COVID-19 and flu are not caused by the same viruses. Furthermore, there is no vaccine against COVID-19 available as of September 2020.
COVID-19 and the flu are both viral respiratory illnesses, however they are caused by very different viruses that belong to two distinct and separate families of viruses. SARS-CoV-2, the virus responsible for COVID-19 is not a strain of flu. Although flu shots are now being distributed in preparation for the upcoming 2020-2021 flu season, the vaccines are not mixed with a COVID-19 vaccine. No vaccine is available against COVID-19 as of September 2020.

FULL CLAIM: The U.S. CDC encourages the use of a “[COVID-19] flu shot” on children.


A claim circulated in September 2020 alleging that the U.S. Centers for Disease Control and Prevention (CDC) is encouraging patients to take an “untested [COVID-19] flu shot”. This claim also suggests that COVID-19 is caused by a strain of flu virus. This claim is inaccurate as no vaccine for COVID-19 is ready as of 18 September 2020. Furthermore, COVID-19 and flu are distinct diseases caused by different viruses.

Firstly, it is inaccurate to claim that COVID-19 is caused by a strain of flu virus. While both the flu and COVID-19 are viral respiratory infections, they are caused by two completely different viruses from two separate families of viruses. The virus responsible for COVID-19 is SARS-CoV-2[1]. Similar to living things, viruses are classified based on a system of biological taxonomy, which contains multiple ranks or levels, named Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species, and Strain. SARS-CoV-2 belongs to the family of viruses named Coronaviridae, to the genus—which is a further subdivision of the Betacoronavirus family, and to the subgenus Sarbecovirus. It is the same classification as SARS-CoV-1, which was responsible for the 2003-2005 SARS outbreaks. Like the other members of Coronaviridae, the genome of SARS-CoV-2 contains a single strand of RNA.

On the other hand, flu is caused by four genera of influenza viruses: Alphainfluenzavirus, Betainfluenzavirus, Deltainfluenzavirus, and Gammainfluenzavirus, all belonging to the family Orthomyxoviridae. Their genome is also made of RNA, but as opposed to the Coronaviridae family, it is not single-stranded. Instead, it is segmented into separate strands. These features altogether demonstrate that SARS-CoV-2 is not a strain of influenza and COVID-19 is not a type of flu.

Secondly, there are no approved vaccines for COVID-19 as of September 2020, except in Russia and China. The New York Times has published a Coronavirus Vaccine Tracker detailing scientists’ efforts toward the development of a COVID-19 vaccine. Among the frontrunners, nine are in Phase III trials, and five are approved for limited use in Russia and China. None have been approved in the U.S. and therefore no COVID-19 vaccine is available for distribution in the U.S.

Thirdly, the U.S. Food and Drug Administration released the composition of the flu vaccines that will be available in the U.S. for the 2020-2021 season. This composition is updated each year to adapt to the currently circulating flu strains. All the listed quadrivalent and trivalent flu vaccines contain only strains from influenza A or influenza B. No other influenza viruses or viruses from other families are present in the flu vaccine.

In summary, the claim that the CDC encouraged the vaccination of people with a “[COVID-19] flu shot” is inaccurate. Flu and COVID-19 are caused by different viruses and there is no such thing as “[COVID-19] flu”. Furthermore, no COVID-19 vaccine is available as of September 2020. The composition of the flu vaccines for the 2020-2021 season has already been decided and the vaccine contains only influenza virus strains.


Reuters also fact-checked this claim and found it to be false.



Published on: 20 Sep 2020 | Editor:

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