Immunity against whooping cough lasts only a few years

The average duration of immunity against whooping cough after vaccination against diphtheria, tetanus, pertussis with an acellular component / currently the immunization calendar of Bulgaria includes a combined five-component vaccine that protects against the following diseases – diphtheria, whooping cough with an acellular component, inactivated poliomyelitis vaccine , conjugate vaccine against Haemophilus influenzae type B/.

“Recently, a number of relatively small studies have emerged showing that the DTaP vaccine does not protect as long as previously thought, but our meta-analysis provides the first categorical and accurate data on this problem” – this is what Ashleigh McGirr, one of the co-authors of this meta-analysis, said.

Recently published reports of a worsening of the pertussis epidemiological situation in a number of countries indicate that the possible reason for this is the too rapid extinction of acquired immunity after DTaP vaccination.

Ashleigh McGirr, MPH and David N. Fisman, MD, MPH, FRCPC conducted a scientific review and meta-analysis to assess the duration of protective immunity against pertussis after 3 and 5 doses of DTaP.

In their research paper, they compared data from 6 studies conducted after 6-dose immunization and 6 studies conducted after 3 doses. All these studies were conducted in the territories of the USA, Germany, Italy, Sweden and Senegal.

The final immune intensity regression model showed that each year starting from the last dose of DTaP vaccine, a person’s risk of developing pertussis increased by 33% with no significant differences between the 3- and 5-dose schedules.

Based on the obtained model for the average duration of protection provided by DTaP vaccines, the scientists concluded that 3 years after the last immunization with the DTaP vaccine, its effectiveness did not exceed 85% and only in 10% of the children who were given it this vaccine, retain their immunity to whooping cough 8.5 years after the last dose of it.

“It is possible that our study will lead to a revision of the existing schemes for immunization of children in the direction of reducing the interval between the administration of vaccines and increasing the amount of doses for revaccination” – this is stated by one of the co-authors of the meta-analysis.

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“Physicians should be aware that the duration of the protective effect of the DTaP vaccine is much shorter than previously thought.

Based on this information, it is possible that in cases of high risk of contracting whooping cough, they may recommend that their patients receive vaccinations at shorter intervals and larger doses of diphtheria, tetanus, and < strong>whooping cough, especially in those who are in adolescence “- he also points out.

Dr. Nicole Guiso of the Institut Pasteur in Paris, France, commenting on this study noted: “The fact that subunit vaccines are unable to provide long-term immunity is well known.

In addition, we should not forget that the duration of immunity after a pertussis disease is also relatively short. Under such conditions, it would be difficult to expect different results, since it is impossible for scientists to create a vaccine that provides better immunity than a disease from nature itself. It is also important to note that a person can get sick from whooping cough. 2-3 times in your life. “

Dr. Gusot continues: “To improve the epidemiological situation, we must first of all increase the coverage of immunizations and reach more than 90% of preschool children with 4 doses.”