By Mark DaCosta-Following an alarming spike in the number of cases of dengue fever infections in Guyana, the Ministry of Health released a statement earlier this week. While the statement contained verifiably accurate scientific information about the disease, as well as unverifiable statistics and purported responses by the People’s Progressive Party (PPP) government of Guyana, the press release made no mention of the fact that there are vaccines available to prevent the disease.
Additionally, in a recent interview with the government-controlled Guyana Chronicle, Adviser to the Minister of Health, Dr Leslie Ramsammy, who is a former minister of health, made no mention of vaccines. Instead, there appears to be an effort by government to downplay and minimise the serious nature of the current health emergency.
This publication notes that two vaccines have been approved to prevent all four variants of dengue: Qdenga and Dengvaxia.
The question arises as to why the PPP government appears to be avoiding informing Guyanese that vaccines are available? Additionally, are any efforts being made by the government to procure dengue vaccines?
About Qdenga (vaccine)
Qdenga is a vaccine that helps protect against dengue disease. The vaccine can be given to adults, adolescents and children from 4 years of age.
This vaccine contains attenuated (weakened) versions of dengue virus serotypes (varieties) 1, 2, 3 and 4.
The vaccine is given as an injection under the skin of the upper arm. The vaccination course consists of 2 injections given 3 months apart.
This vaccine contains attenuated versions of the 4 virus serotypes. These versions cannot cause the disease, but they ‘teach’ the immune system (the body’s natural defences) to defend the body against the virus.
When a person is given the vaccine, the immune system identifies the attenuated serotypes as foreign and makes antibodies against them. When a person is later exposed to the virus, the immune system recognises it and can quickly make many more antibodies, which then neutralise the virus before it can cause dengue disease.
This vaccine was shown to be effective at preventing fever due to dengue disease in children and adolescents in the 12 months following the second injection. In a main study in 8 countries in Latin America and the Asia Pacific region, about 20,000 children between the age of 4 to 16 years were given Qdenga or placebo (a dummy injection). The study showed a reduction by 80% in the number of fever cases caused by confirmed dengue disease in those who received the vaccine (61 cases in 12,700 children) compared with those given placebo (149 cases in 6,316 children).The vaccine also reduced hospitalisation due to dengue by 90%. In the 18 months after receiving the second injection, 0.1% (13 out of 12,700) of children given the vaccine were hospitalised because of confirmed dengue, compared with 1.0% (66 out of 6,316) of children given placebo.
About Dengvaxia (vaccine)
For the prevention of dengue disease caused by dengue virus serotypes 1, 2, 3 and 4. DENGVAXIA is approved for use in individuals 6 through 16 years of age with laboratory-confirmed previous dengue infection and living in endemic areas.
Dengvaxia is effective at reducing the number of cases of dengue disease in people aged between 6 and 45 years who have had the infection in the past. However, people who have not had dengue infection in the past may have a higher risk of severe dengue disease if they become infected with the virus after vaccination with Dengvaxia. Therefore, the vaccine should only be given to people who have had a previous dengue infection, as confirmed by laboratory testing.
Dengvaxia’s side effects are usually mild or moderate and do not last longer than three days.
The European Medicines Agency therefore decided that Dengvaxia’s benefits are greater than its risks and it can be authorised for use in the EU in areas where dengue disease is endemic.
In Guyana, according to reports, in the last few months there have been some 100 new cases of dengue each week. According to Ministry of Health statistics, there are currently a high number of active cases, with deaths in 2023, in the double digits.
