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

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

73.1-fold). For each group, the number of samples (N =) and the mean number of selected B cells or T cells are shown below the x-axis. In the latter group, convalescent donors were coded based on receiving one dose (magenta) or two doses (cyan) of mRNA vaccines. Whiskers indicate the vernal range. A two-sided Mann-Whitney U test was used and P < 0.05 was considered statistically significant and highlighted in red. IL-2: interleukin-2, IFN-γ: interferon-gamma. credit: Nature Communications (2022). DOI: 10.1038 / s41467-022-30340-5″ Width =”800″ height =”383″/>
Memory B and T cell responses in different vaccination groups. Receptor-binding domain (RBD)-specific IgG produces memory B cell (a) and T cell specific (b–d) spike 1 (S1) responses in different groups of vaccinated individuals. Icons represent individual subjects and horizontal black lines indicate the median. The cut-off value (red dashed line) and the number of mean fold differences between groups are indicated. As the mean cell count for RBD was zero for two groups, the number of variable differences compared to inactivated + single dose of mRNA vaccine was estimated to be more than the highest calculated value (>73.1-fold). For each group, the number of samples (N =) and the mean number of selected B cells or T cells are shown below the x-axis. In the latter group, convalescent donors were coded based on receiving one dose (magenta) or two doses (cyan) of mRNA vaccines. Whiskers indicate the vernal range. The two-sided Mann-Whitney U test and P Nature Communications (2022) were used. DOI: 10.1038 / s41467-022-30340-5

Vaccines based on the inactivated SARS-CoV-2 virus are commonly used in developing countries due to their low cost. New research from Karolinska Institutet in Sweden shows that a booster dose of the mRNA vaccine for individuals who received two doses of the inactivated vaccine provides the same level of protection against COVID-19 as three doses of the mRNA vaccine. The results were published in the journal Nature Communications.

“Our results indicate that a single booster dose of mRNA vaccine, as a complement to cheaper and less effective inactivated vaccines, is sufficient to achieve an immune response. “gold standard” Measured after three doses of mRNA vaccine.” Says Qiang Pan Hammarström, a professor in the Department of Biological Sciences and Nutrition, Karolinska Institutet, who led the study. “This could 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.

It could benefit billions of people

“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,” Qiang Pan Hammarström says. “The more widespread use of mRNA-boosted shots may also help China weather 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.

Emerging sub-variables omicron

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

“We will assess 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,” Qiang Pan Hammarström says.


Pfizer Protective Booster Over 50% Against Omicron


more information:
Fanglei Zuo et al, Heterologous immunization with an inactivated vaccine followed by an mRNA booster elicits strong immunity against the SARS-CoV-2 omicron variant, Nature Communications (2022). DOI: 10.1038 / s41467-022-30340-5

Provided by Karolinska Institutet

the quote: mRNA-booster vaccines may be a good investment in developing countries (2022, May 13) Retrieved May 13, 2022 from https://medicalxpress.com/news/2022-05-mrna-booster-vaccines-good-investment.html

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2022-05-13 13:45:18

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