The Covid-19 pandemic has resulted in the prolonged closure of schools islandwide, depriving children not only of their classroom learning, but disrupting their regular normal immunisation schedules against preventable diseases despite efforts of the Epidemiology Unit to sustain the program at all costs.
The Sunday Observer spoke to Consultant Epidemiologist, Epidemiology Unit, Ministry of Health Dr Deepa Gamage to find out how the Unit coped and most importantly why vaccination must continue.
Excerpts
Q: The Regional Director, WHO South-East Asia has said at the recent 74th Regional Committee meeting that the vulnerability to vaccine preventable diseases has increased with the Covid pandemic and the number of unvaccinated children has increased to 4.9 million in 2020 as against 3 million in 2019. How does Sri Lanka’s Expanded Immunisation Program (EPI) stand in comparison to these figures?
A: Sri Lanka has a high vaccine acceptability and demand by parents. During 2020, even with Covid-19 pandemic, the country’s vaccination coverage for all vaccines was very high except school based HPV and a Td vaccination. Due to schools being closed on most days during 2020-2021, school based vaccination for children could not be completed. However, measures have been taken to open vaccination centres in all MOH areas to provide these two types of vaccination also to unvaccinated children throughout the country.
Q: The WHO Regional Director also noted that the Covid pandemic has impacted implementation strategies for Measles and Rubella elimination in the region. Does this apply to Sri Lanka’s immunisation program as well?
A: The Measles/Mumps and Rubella (MMR) vaccine is given in our country to sustain measles and rubella immunity as a 2-dose schedule at nine months and three years. In 2020, vaccination coverage achieved 96 percent for each dose of MMR 1st and 2nd doses. If any child missed this vaccination due to the Covid-19 pandemic, public health midwives in MOH areas have been instructed to identify children and vaccinate them.
Q: Didn’t Sri Lanka achieve its elimination goal for both these programs a few years ago?
A: Sri Lanka was certified as endogenous Measles eliminated in 2019 and endogenous Rubella eliminated in 2020. However, we need to maintain the certification status as Measles outbreaks are ongoing in some other countries. If we are unable to maintain a high level of vaccination and maintain early case detection, we may lose our elimination status.
It is important to realise that Measles can be imported into the country through ports of entries at any time with global travels. Our surveillance system should detect all possible cases of fever and rash and need to investigate in the laboratory at the Medical Research Institute to exclude as non-measles, non-rubella cases. Vaccination against these diseases should continue at a very high level to ensure that imported cases will not further transmit.
Q: Sri Lanka was commended for achieving high routine immunisation coverage and its excellent progress in vaccinating children against many other preventable diseases including Small Pox, Poliomyelitis, whooping cough, neonatal tetanus, Japanese Encephalitis and reduction of mortality and morbidity due to Haemophililias influence B disease. Is the scenario the same today?
A: Yes, Small Pox is globally eradicated. Other diseases are also dangerous diseases with a lot of complications. Poliomyelitis and Neonatal Tetanus are certified as eliminated. Other vaccine preventable diseases are very low due to vaccination.
Q: How do vaccines work? How do they build up a child’s developing immune system against diseases? Doesn’t nature provide those facilities inside our body?
A: Vaccines develop protection without causing the disease. Vaccines for specific diseases cause specific immunity to protect from the particular diseases. The immune system in the body has the ability to give some protection without vaccines. If the disease causing organism is more virulent, the body’s natural immunity is not adequate. If the child gets the disease, it leads to developing disease specific immunity. But if the disease is severe, the child can get complications and die before developing the immunity. That is why vaccination is a must and should be done to develop disease specific protection.
Q: Can vaccinating a child against one preventable disease protect him or her against another disease?
A: No, there will not be cross protection against various diseases. Children should get vaccination for each disease advised to vaccinate through the National Immunisation schedule.
Q: What are the health complications that are likely to arise if a child is not vaccinated against Measles, for example?
A: There are short term and long term complications. Complications include pneumonia, diarrhaea, hearing problems, eye problems and blindness, brain infection and even death. Malnutrition, affecting other organs such as liver, heart and pancreas can lead to long term consequences. Measles can cause even brain problems called Sub Subacute sclerosing Panencephalitis (SSPE) Encephalitis (SSPE) even after 3-5 years, which is not curable. The child will die.
Q: What about Rubella?
A: Rubella is a mild disease on appearance, but causes severe congenital abnormalities to a newborn child, if a pregnant mother contracts the disease during pregnancy. All women should be protected against Rubella by the time they reach child bearing age and prevent transmission of the disease.
Q: What are the principles that determine immunisation schedules?
A: The main consideration in the vaccination program is protecting people from high burden diseases. Other concerns include ensuring efficacious vaccines that adequately protect the disease, while adhering to safety guidelines and prequalification issued by the WHO. The best age to get the maximum protection and the number of doses are considered as principles to determine the National Immunisation Schedule.
Q: What is the present EPI vaccination schedule?
A: BCG for childhood TB prevention is given 24 hours after birth at hospitals, failing which through the Medical Officer of Health Offices. Two and four month Pentavalent vaccine (DPT,Hib B, Hep B) and polio vaccines (oral polio and injectable polio), followed by six months with Pentavalent and oral polio vaccine (OPV).
At nine months, MMR vaccine, 12 months Live JE vaccine, 18 months Triple (DPT vaccine) are given. It is important to give MMR 2nd dose at three years of age and DT at five years, aTd at 12 years (Grade 7 in school), as received vaccines at childhood would be a boost to give long term protection. The HPV vaccine is given to Grade 6 girls through school based programs.
Those who have missed the rubella containing vaccine dose during their childhood will receive one MMR dose at the reproductive age before becoming pregnant (at least three months before).
Q: What about pregnant mothers?
A: A pregnant mother will receive the Tetanus toxoid vaccine to protect the newborn from tetanus (neonatal tetanus) as two doses in the first pregnancy, followed with each dose in consecutive pregnancies till they receive five doses which would give protection for 10 years.
Q: The main objectives of the National Immunisation Program were laid down some years ago. What are they?
A: The objectives are updated from time to time with global and country specific strategies. The most updated objectives are 1) Eradication of poliomyelitis 2) Eliminate and sustain free status of measles, rubella/CRS, maternal and neonatal tetanus, whooping cough, diphtheria 3) prevention, control and prevention of outbreaks of Miliary TB, Japanese encephalitis, diseases caused by Haemophyllus B influenza, and mumps 4) prevention of chronic liver diseases caused by Hepatitis B and prevention of HPV related cervical cancers.
Q: There have been instances of allergic reactions to a vaccine. E.g. the Rubella vaccine some years ago in Sri Lanka. What kind of allergies should we look for?
A: Vaccine safety is ensured through WHO pre-qualification and registration at the National Medicinal Drug Regulatory Authority. However, vaccines like other drugs and chemical products can have some unwanted effects including allergic reactions. But all precautions are taken by the health staff to prevent such adverse events. Before vaccination, the medical officer will examine the child and ask the mother about specific allergies and the doctor will decide the eligibility to vaccinate. All vaccination centres keep emergency treatment drugs and all staff manning the Centres are trained in managing emergencies and taking emergency cases to a hospital if needed.
Q: We hear of vaccine mix-ups or untrained persons using wrong strengths that are not potent enough, which beg the questions; how safe and effective are these vaccines? What is the assurance that the Epidemiology Unit can give to our readers on this matter?
A: All vaccines given through the National Immunisation Program are safe and effective. All measures have been taken to safely store vaccines in a specialised refrigerator (ILR) at all MOH offices to maintain a cold chain until take them to the vaccination centres. We, the Epidemiology Unit, train all public health and hospital vaccination staff from time to time on vaccines and the vaccination process to ensure to safely deliver vaccines to get the maximum effects. Parents are allowed to ask any question and can get clarifications about their doubts from the vaccination centre, MOH office of the area, treating Paediatricians and Physicians, Regional Epidemiologists or from the Epidemiology Unit, De Saram Place, Colombo 10.
Q: Many parents worry that multiple vaccines will overload their child’s immune system. Your comments?
A: Vaccines are combined in a way that it can be given to a child without causing problems. There will not be overloading to the immune system for the vaccinations given through the national immunisation schedule. Parents should not be worried on this matter as experts have taken the decision based on reviewing all evidence with maximum precautions for the betterment of the child’s protection from these deadly diseases.
Q: What is herd immunity?
A: Following high vaccination coverage which has helped develop protective level immunity, the disease transmission will break in the community. An unvaccinated person will not get the disease if transmission is blocked due to high population level immunity. However, if the unprotected /unvaccinated person comes into direct contact with an infected person, he or she could get infected.
Q: What is your message to parents of unvaccinated or not fully immunised children?
A: We are facing a challenging time with the Covid-19 pandemic. Your child must have got the vaccination at the appropriate age or may have got delayed due to lockdowns. Make sure your child gets all vaccines provided through the national immunisation schedule at the recommended age, as mentioned in the CHDR of the child.
If delayed, contact your area Public Health Midwife or MOH at the earliest to receive the delayed vaccine doses and continue with age appropriate next vaccination for your child to save your child and save others in the community.