School uniforms are neatly ironed, books are freshly covered, lunch boxes are packed, and classrooms are once again filled with chatter. But for many parents, the start of a new school term also brings a less welcome routine. Within weeks, a child comes home with a runny nose, sore throat, cough or fever. Soon, a sibling catches the bug, and before long, even the parents may find themselves feeling under the weather.
While this annual cycle may seem like bad luck, there’s a scientific reason behind it. HT Lifestyle spoke to Dr Lokesh Mahajan – Head of Paediatrics at Marengo Asia Hospitals, Faridabad – who explains why infections tend to spread so quickly when schools reopen. He points out, “The first few weeks after schools reopen create the perfect environment for common viruses to spread among children. Parents often worry that frequent illnesses mean their child has poor immunity. In most cases, that’s not true. The immune system is simply encountering a large number of new viruses after weeks of relatively limited exposure during the holidays.”
Why schools become hotspots for infections
According to Dr Mahajan, “During vacations, children spend most of their time at home or with a familiar group of family members and friends. Their exposure to germs is relatively limited and predictable. The moment schools reopen, however, that changes dramatically.”
A typical classroom accommodates 35 to 50 students who spend six to eight hours together every day. They share desks, books, stationery, playground equipment and enclosed indoor spaces. Every child brings along viruses and bacteria acquired from different households, neighbourhoods and holiday destinations.
“When children come together after a long break, they are suddenly exposed to many germs their immune systems haven’t encountered before. As the body develops immunity against these infections, mild illnesses such as colds, sore throats and fever become common,” explains the paediatrician.
The role of nutrition
Exposure to germs alone does not determine whether a child falls sick. Nutrition is another important factor influencing how effectively the immune system responds. According to Dr Mahajan, “A balanced immune response depends not only on exposure to germs but also on adequate nutrition. Children who have deficiencies of essential vitamins and minerals may find it harder to respond effectively when exposed to common infections.”
Nutrients to support a healthy immune system
While there is no single food or supplement that can prevent infections, the paediatrician recommends ensuring that children consume a balanced diet rich in essential micronutrients, including the following:
- Vitamin C: Supports the production and function of white blood cells and acts as an antioxidant.
- Vitamin D: Contributes to normal immune function, and deficiency has been associated with an increased risk of respiratory infections.
- Zinc: Plays a vital role in the development and activity of immune cells.
- Vitamin A: Helps maintain healthy mucosal barriers in the nose, throat and respiratory tract, which serve as the body’s first line of defence against germs.
- B-complex vitamins: Particularly B6, B12 and folate are essential for the production and functioning of immune cells.
Simple habits can make a difference
Dr Mahajan emphasises that no child can completely avoid infections after returning to school. In fact, encountering common viruses is part of how the immune system matures over time. However, parents can help reduce the frequency and severity of illnesses by encouraging a nutritious diet, adequate sleep, regular physical activity and proper hydration. Teaching children to wash their hands regularly, cover their mouth while coughing or sneezing, and avoid sharing water bottles or utensils can also help limit the spread of infections.
He highlights, “Parents should not panic every time a child develops a cold after school reopens. Most of these illnesses are self-limiting and help the immune system build long-term protection. The focus should be on maintaining good nutrition, healthy lifestyle habits and ensuring children receive all recommended vaccinations. But with good hygiene, balanced nutrition and a little preparation, parents can help children navigate the back-to-school season with fewer interruptions to learning and play.”
Foods that provide immune-supporting nutrients
Dr Mahajan stresses that parents don’t necessarily need to rely on supplements unless advised by a doctor. Most children can get these essential nutrients through a balanced, varied diet that includes seasonal fruits, vegetables, dairy, whole grains and protein-rich foods. He outlines the following sources:
- Vitamin C: Include citrus fruits such as oranges, sweet lime and lemons, along with guava, amla (Indian gooseberry), kiwi, strawberries, tomatoes, capsicum and broccoli. Guava and amla are among the richest natural sources of vitamin C.
- Vitamin D: The body produces vitamin D when the skin is exposed to sunlight. Dietary sources include egg yolks, oily fish, mushrooms, fortified milk and dairy products.
- Zinc: Good sources include lentils, chickpeas, kidney beans, peanuts, pumpkin seeds, sesame seeds, cashews, milk, yoghurt, eggs and lean meat.
- Vitamin A: Orange and yellow vegetables such as carrots, pumpkin and sweet potatoes are rich in beta-carotene, which the body converts into vitamin A. Other sources include spinach, fenugreek leaves, drumstick leaves, mangoes, papaya, eggs and dairy products.
- B Vitamins (B6, B12 and Folate): Whole grains, bananas, potatoes, green leafy vegetables, beans, lentils and nuts provide several B vitamins. Vitamin B12 is found naturally in milk, curd, paneer, cheese, eggs, fish and meat, making dairy products particularly important for vegetarian children.
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
Dr Lokesh Mahajan is a Senior Consultant and Head of the Department for Pediatrics and Neonatology at Marengo Asia Hospitals in Faridabad, Haryana. With over 20 years of experience, he specialises in pediatric infectious diseases, pediatric intensive care, and neonatal intensive care.
