Vaccine services: Painful lessons from major countries

According to Associate Professor, Dr. Phan Trong Lan, Director of the Pasteur Institute in Ho Chi Minh City, vaccine complications are always present, but people skipping vaccinations and waiting for service vaccines is even more dangerous.

Children should be vaccinated to prevent disease outbreaks.

History of disease in children

According to Associate Professor Lan, in 1974, in the UK, an author reported 22 cases of children with developmental delays and epilepsy after being vaccinated with whole-cell pertussis vaccine. This information led to a sharp drop in the vaccination rate in the UK from 81% to 31% in the following years, resulting in 100,000 children contracting pertussis and 31 deaths. This report also reduced the vaccination rate and increased the number of deaths due to pertussis in Japan, Sweden and Wales. However, many later controlled studies have shown that the rate of developmental delays and epilepsy in children after being vaccinated with whole-cell pertussis vaccine is similar to that of children who were not vaccinated, and many of these children actually had Dravet syndrome (Na channel transport defect).

Another case of the connection between the MMR (Measles-Mumps-Rubella) vaccine and autism was published by an author in a prestigious journal in the world (Lancet) in 1998. The article mentioned 12 cases of intestinal infections and autism related to MMR. Immediately, the MMR vaccination rate dropped and an outbreak occurred in the UK. Many studies had to be conducted afterwards and came to the conclusion that there was no connection between autism and MMR. The author of the article was later convicted of data fraud and having a conflict of interest when publishing the above information. The article was completely retracted from the above journal after 12 years of publication.

And in Vietnam, in 2013, due to vaccine complications, people did not let their children get vaccinated, resulting in a measles outbreak that took the lives of nearly 150 children. This is truly regrettable.

Acellular vaccines can cause outbreaks

Comparing Quinvaxem vaccine with other vaccines such as 5 in 1, 6 in 1 currently used in Vietnam, Associate Professor Lan said the basic difference is the composition of the whole-cell pertussis vaccine (Quinvaxem) or acellular (service vaccine). The transition from using whole-cell pertussis to acellular pertussis has been implemented in many countries and the limitations of this vaccine have also been noted in countries with developed economies.

In the United States, before the vaccine, whooping cough infected more than 200,000 people and killed 10,000 each year. After the introduction of the whole-cell pertussis vaccine in 1976, the rate of whooping cough decreased by 95%. However, since the switch to acellular pertussis in 1990, whooping cough outbreaks have begun to occur in the following years, specifically whooping cough outbreaks tend to occur in cycles and are most severe in 2005, 2010, and 2014.

The epidemic has a cycle of about 5 years and is caused by the decline of protective immunity to acellular pertussis and the accumulation of these cases each year. The 2014 epidemic in the US is considered the largest in the past 50 years. Even with the addition of a multi-dose booster vaccination schedule (in addition to the 3 basic doses, booster vaccination for children 4-6 years old, 11-12 years old and pregnant women in the 27th to 36th week), currently, each year, in the US, there are still 10,000-40,000 cases and 10-20 deaths from this disease.

A 2015 WHO report on pertussis rates in 19 countries (4 upper middle-income countries and 15 high-income countries) showed that although there were no global pertussis outbreaks, in 5/19 countries (Australia, Chile, Portugal, UK, USA), pertussis outbreaks actually increased. Of these 5 countries, 4 had previously switched from whole-cell pertussis to acellular pertussis (only Chile used whole-cell pertussis and the pertussis outbreak in Chile was attributed to low vaccination coverage). In 4 countries (Australia, Portugal, UK, USA), especially in Australia, UK, USA, studies showed that the main cause was the reduction in protective efficacy when injecting acellular pertussis vaccine, leading to the accumulation of susceptible cases and then periodic outbreaks, even though the vaccination coverage in these countries was quite high, over 85%. Pertussis outbreaks have not been observed in countries that use whole-cell pertussis vaccine and have high vaccination rates.

The issue of switching from whole-cell to acellular pertussis requires consideration of the ability to control outbreaks, ensure vaccine supplies for booster doses, and vaccination strategies for pregnant mothers to protect children immediately after birth and limit deaths in the event of a pertussis outbreak due to the use of acellular pertussis vaccines.

According to Infonet