mRNA-booster vaccines may be a good investment in developing countries

Vaccines based on the inactivated SARS-CoV-2 virus are commonly used in Developing countries because of its low cost. New search from Karolinska Institute in Sweden Shows that a booster dose of mRNA vaccine for individuals who received two doses of the inactivated vaccine Offers the same level of professionalstection against COVID-19 with three doses of mRNA vaccine. The results were published in the journal Nature Communications.

“Our results indicate that a single booster dose of mRNA vaccine, as a supplement to cheaper and less effective inactivated vaccines, is sufficient to achieve the ‘gold standard’ immune response measured after three doses of mRNA vaccine,” says Qiang Pan Hammarström, Professor in the Department of Biological Sciences and Nutrition, Karolinska Institutet, which led the study. “This would potentially be a good investment even in resource-poor countries to protect against severe COVID-19.”

The study included 175 healthy volunteers with different vaccination histories. The researchers investigated the presence of antibodies and memory B and T cell responses against SARS-CoV-2 after vaccination and booster shots with an inactivated vaccine (Sinovac/Sinopharm), an mRNA vaccine (Pfizer-BioNTech/Moderna), or a combination of both. .

The results showed that a booster dose of mRNA vaccine for individuals who received two doses of the inactivated vaccine strongly increased levels of neutralizing antibodies and memory B and T cells directed against SARS-CoV-2 variants of concern, including Omicron. Levels were significantly higher than those of subjects receiving three doses of the inactivated vaccine, and similar to those of individuals receiving three doses of the mRNA vaccine or a boost of the mRNA vaccine after natural infection.

“Given that nearly half of the COVID-19 vaccine doses distributed worldwide are inactivated vaccines, an improved mRNA boost strategy could benefit billions of people in our fight against emerging variables of concern,” says Qiang Pan Hammarström. “The more widespread use of mRNA-boosting shots may also help China weather the current lockdowns.”

One limitation of the study is the relatively low number of participants; Only 16 individuals received vaccination with two doses of inactivated vaccine followed by mRNA vaccine augmentation. Furthermore, the average age of the study participants was 36 years old, which is younger than the world population average. Thus, the results must be confirmed in large-scale longitudinal studies involving different age groups.

The researchers will now continue to study the effect of a heterogeneous vaccination strategy on emerging variants of SARS-CoV-2.

“We will evaluate for the first time whether this vaccination strategy can neutralize the two emerging sub-variables of Omicron BA.4 and BA.5, underlying the new wave of COVID-19 in South Africa,” says Qiang Pan Hammarström.

The study was conducted within the ATAC research consortium, funded by the European Commission in response to the COVID-19 pandemic and coordinated by Karolinska Institutet. Other members of the consortium include the Institute for Research in Biomedicine (Switzerland), the Policlinico San Mateo in Pavia (Italy), the Technische Universitaet Braunschweig (Germany) and the European Commission Joint Research Center. Collaboration with Stockholm University (Sweden), Tehran University of Medical Sciences (Iran), Shahid Beheshti University of Medical Sciences (Iran), and Peking University Health Sciences Center (China) was also instrumental in realizing the study.

The study was also funded by the Swedish Research Council and the Knut and Alice Wallenberg Foundation. The researchers declare that there is no conflict of interest.

the post: Heterogeneous immunization with an inactivated vaccine followed by an mRNA booster generates strong immunity against the SARS-CoV-2 Omicron variant. Vangeli Zou, Hassan Abulhassani, Lecon Do, Antonio Peralla, Federico Bertolio, Leer de Campos Mata, Hui Wan, Marin Schubert, Irene Casanetti, Yating Wang, Jose Camila Sammartino, Rui Sun, Stelios Flaciotis, Federica Berjami, Makiko Kumagai-Brish , Johnny Andrell, Zhaoxia Zhang, Yentong Zoe, Esther Veronica Wenzel, Luigi Calzulay, Luca Chara, Zahra, Zahra Fausto Baldante, Michael Hust, Lennart Hammerström, Harold Marcotte and Chiang Baan Hammerström. Nature Communicationsonline 13 May 2022, doi: 10.1038/s41467-022-30340-5.

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2022-05-13 17:21:22

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