History of polio epidemics in the USSR and Russia. Reference

How does infection occur and who is at risk?

The routes of infection with polio mainly come down to the penetration of the virus through the digestive tract - if water, food or hands have previously come into contact with contaminated substances. For example, feces of a sick person get into a pond, and then when swimming, the patient gets the virus along with the contaminated water. The causative agent of the disease is poliovirus.

You can become infected through water, food, dirty clothes, etc. At risk are:

• children under 7 years old. Poliomyelitis occurs much more often in children than in adults;
• Pregnant women;
• people with very weakened immune systems. This can be facilitated by various diseases, as well as disorders at the endocrine level, periods after operations, etc.;
• people suffering from immunodeficiencies.

The risk of infection is higher during the warm season: summer or autumn. The virus is very tenacious; in a humid environment it can live up to 4 months.

Victory of Soviet scientists

The fate of the live polio vaccine and its further role in global epidemiology was decided by Sabin’s meeting with the Soviet scientist Mikhail Chumakov. At that time, Mikhail Petrovich was in America - together with his wife and colleague, he was sent to the States to exchange experiences. Chumakov quickly seized on this theory, and after some time several thousand doses of polio vaccines were brought to the USSR.

The drug, which had not been fully tested, was tested on everyone - myself, relatives, colleagues. Understanding perfectly well the danger of such experiments, none of my relatives objected. Everyone knew that this was necessary to protect their children from a terrible disease.

Production of live Sabin vaccine has begun at the Polio Institute. However, the Ministry of Health did not approve of this idea - “if the drug was abandoned in America, why should we test and produce it”? Chumakov decided to take a risk and carried out a successful vaccination, after which the polio epidemic was ended in just a year and a half, and the vaccine was exported to more than 60 countries.

Symptoms of polio and course of the disease

The polio virus causes the following symptoms:

• signs of intoxication: nausea, vomiting, diarrhea, rash;
• cold-like disorders: cough, runny nose, sore throat, difficulty breathing and swallowing;
• fluctuations in blood pressure, fatigue, general poor health, headache;
• in rare cases - various types of paralysis that can lead to the death of the patient.

It is important to note that in 90% of cases, polio has no symptoms and does not affect the nervous system. And in 10% of cases there are very severe forms, involving inflammation of the membranes of the brain - with serious consequences, even fatal.

The incubation period of polio is quite short - it does not exceed 5 days. In this case, recovery in the case of a mild form occurs within 3 days. However, as we have already said, there are also complex forms - they are quite rare, but extremely dangerous. In this case, treatment may last for months, years, or may be completely useless.

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Hilary Koprowski, Herald Cox and Albert Sabin

While Jonas Salk was working on a polio vaccine with killed virus (inactivated polio vaccine, IPV), three groups of scientists—Koprowski, Cox, and Sabin—were creating a live vaccine. Their main idea was that only a live virus that enters the body naturally (through the mouth, i.e. orally) can give a person complete protection against infection. This idea has been fully confirmed by practice. It was OPV (oral polio vaccine) that made it possible to defeat polio in most countries of the world.

The “killed” vaccine is based on wild polio virus treated with formaldehyde. A live vaccine is an artificially bred strain of the virus that, during the selection process, has lost the ability to cause paralysis, but allows the body to develop immunity to itself, and at the same time to the wild virus. The killed vaccine (IPV) can be compared to a stuffed wolf, and the live vaccine (OPV) can be compared to northern sled dogs (Malamute, Husky), which, despite their external resemblance to a wolf, have been faithful friends of humans for many years.

By the end of the 1950s, Koprowski, Cox and Sabin had developed their own strains of the virus for OPV. It was a long and difficult job. In fact, what is easier - to make a stuffed animal of a dead wolf or to breed a new breed of dog? Hilary Koprowski, Herald Cox and Albert Sabin were the breeders who created a new “breed” of the polio virus. Koprowski said: “The labor to create a killed vaccine cannot be compared with the labor spent on weakening a live virus and turning it into a vaccine strain, just as it is impossible to compare the labor that is required to kill a cow in a slaughterhouse or raise an adult animal from a newborn calf.” .

By the mid-1950s, Koprowski, Cox and Seibin had already carried out the first tests on humans (mainly on the families and colleagues of scientists, although not only on them), but things did not go further. In the United States, there was little interest in introducing OPV into practice for several reasons.

First, large pharmaceutical companies made good money from the complex production of inactivated vaccines. A live vaccine was much easier to produce; more pharmaceutical companies could obtain a license for production, which would lead to lower prices.

Secondly, many doctors were opposed to the live vaccine. Partly the propaganda of the Salk vaccine worked, partly it was financial considerations. Money was paid for each injection of the inactivated vaccine ($5 for each vaccination), and a mass transition to OPV would deprive doctors of this income.

Thirdly, many remembered the story of the weakened Colmer virus, which caused the death of several children. Live viruses were simply not trusted. Although in vain - after all, live vaccines have been successfully used for many years in the fight against smallpox and yellow fever. Mistrust of live vaccines was greatly fueled by the media, which advertised the Salk vaccine.

Jonas Salk on the Mar. 29, 1954, cover of TIME

Although three American researchers were working on a live vaccine, by the mid-1950s only Albert Sabin had reliable strains.[3][14]

Some foreign sources claim that all three researchers - Koprowski, Cox and Seibin - ultimately managed to create good strains of poliovirus. This is not entirely true: the best viruses were obtained by Seibin, good ones, but not used today, by Koprowski. The latter carried out mass vaccinations in the Congo and other African countries. The Cox vaccine, produced by Lederle, was not safe enough - for example, out of 280,000 residents of West Berlin vaccinated with this vaccine, 48 people got sick and three died. The Cox strain was finally banned for use after the vaccine virus was discovered in the brain of the deceased father of a vaccinated child. After the Sabin vaccine was licensed in America, Lederle produced it. Today, exclusively Sabin viral strains are used throughout the world.

Nadezhda Safronova, RVS

Read more: Poliomyelitis: the problem is returning (end)

How is polio diagnosed?

If obvious symptoms of polio occur, the patient is admitted to an infectious diseases hospital, where an infectious disease specialist takes over the examination. To understand what the reason is, they carry out a number of manipulations, be sure to investigate:

• blood and urine tests;
• materials from the nasopharynx;
• feces;
• cerebrospinal fluid.

All this allows us to find out which pathogen caused the disease and make a correct diagnosis.

Tips for parents

If a child often has allergic reactions or is allergic, then vaccination is possible only during the period of remission. There is no need to use any medications before administering the vaccine.

If your child experiences the following symptoms after vaccination, you should consult a doctor:

· appearance of signs of acute respiratory infections (runny nose, cough, etc.);

· dysfunction of the gastrointestinal tract;

· shortness of breath, decreased muscle tone of the limbs.

We are talking about signs of vaccine-associated polio, which may appear 4-30 days after OPV administration. A visit to the pediatrician is necessary if there is an irregular heartbeat, urticaria or severe headaches.

After vaccination, it is recommended to avoid visiting crowded places. The child should be given more purified water to drink, and allergenic foods should be excluded from the diet.

How the disease is treated in Moscow

Treatment of polio is carried out in an infectious diseases hospital and involves an integrated approach, including:

• strict bed rest. The patient should remain calm, in a favorable environment;
• protection of paralyzed muscles. For this purpose, special splints can be applied;
• physiotherapy. This includes physical therapy, swimming in the pool under the supervision of a trainer, and massage. This also includes electrical stimulation, paraffin applications, UHF therapy and much more. The procedures are aimed at stabilizing the nervous system, helping paralyzed muscles;
• Ventilation Clinical guidelines for polio also suggest major life-sustaining interventions. The use of a mechanical ventilation device is indicated for patients whose paralysis has affected the respiratory system, and therefore threatens respiratory arrest;
• use of special medications.

It is very important that a polio patient be closely monitored, especially when the disease is progressing or not showing significant improvement.

Warning for the unvaccinated

The stated goal of the World Health Organization (WHO) is to eradicate polio, and Russia is also committed to this goal. However, polio is still found in Pakistan, Afghanistan or Nigeria and can also be carried by tourists into the Russian Federation. Therefore, polio vaccination is still recommended, important and necessary.

Everyone should be vaccinated against polio, ideally as early as infancy. People who were not vaccinated as children, or whose vaccination status is unknown, should catch up on polio vaccination.

Prevention of polio

The main preventive measure is vaccination of children, which is carried out at an early age and then again. There is a special vaccination calendar, on the basis of which pediatricians recommend undergoing this procedure. When vaccinated correctly, lifelong immunity and resistance to poliovirus are developed.

If we talk about the prevention of polio at the household level, it means:

• refusal to swim in dirty bodies of water that are not suitable for this;
• compliance with personal hygiene rules;
• refusal of potentially dangerous products. In this sense, raw milk is undesirable - a pathogen is often found in it;
• Quarantine measures if a child with a disease is detected in a children's group. At the same time, all objects and things are processed and disinfected.

Now polio is quite rare - this is due to centralized vaccination, thanks to which children from an early age develop immunity to the polio virus, and therefore calmly tolerate contact with it.

Adverse reactions

The combination polio vaccine, often used in infants, is generally well tolerated. There may be redness or painful swelling at the injection site. Allergic reactions are also possible.

As the immune system reacts to the vaccine, it may temporarily cause various illnesses. These include, for example:

· headaches and aches;

· gastrointestinal discomfort;

· fever and fatigue;

· irritability and chills.

These vaccination reactions usually resolve on their own within 1-3 days.

Questions and answers on the topic of polio

Is it necessary to get the OPV vaccine?

Parents have the opportunity to refuse such vaccination - they can write a written refusal and not undergo this procedure. However, doctors warn against such a decision: remember that if 10% of children get sick, the consequences will be irreversible, and for some children such a refusal will cost their lives. Currently, OPV vaccination is the only way to be 100% protected against the polio pathogen.

How is the polio vaccine given?

The vaccination is done twice, starting from the age of three months. The injection is given intramuscularly and contains the virus killed by formaldehyde.

How effective is vaccination against this disease?

Since the active fight against polio (1988), thanks to vaccination, it has been possible to reduce the number of cases from 350 thousand people per year to 359 cases (in 2014). These data speak for themselves: after receiving the vaccine, the disease becomes harmless and no longer threatens the person.

Development of the first vaccine

The first polio vaccine appeared in early 1952. Its creator was virologist Jonas Salk from the United States. By that time, the disease had spread throughout the globe - in America alone, during 1952, the virus killed more than 3,000 people, and left more than 21,000 paralyzed.

Dead viruses were taken as the basis, since by the time the polio vaccine was created, Jonas Salk was developing a flu vaccine, and while testing the drug on patients, he noticed that killed viruses also triggered a response from the immune system. Almost 20,000 monkeys were involved in the search process. However, the scientist understood that this was not enough, and for large-scale production it was necessary to somehow reproduce the pathogen in test tubes. To implement the idea, Salk took advantage of the achievements of Frederick Robbins, John Enders and Thomas Weller.

The scientist first administered the resulting drug to himself and his loved ones – his three sons and his wife. What was happening was recorded on photos and video cameras - these materials were later used to reassure the population during mass immunization. It turned out that the vaccine was safe and effective, and already in 1954, the untested composition was administered to five thousand school students. Not a single child got sick after vaccination.

Paralytic stage

This is the stage when the patient suddenly suffers from paralysis (within a couple of hours). This stage lasts from 2-3 to 10-14 days. Patients during this period often die from severe respiratory and circulatory disorders. It has the following symptoms:

• flaccid paralysis;
• defecation disorders;
• decreased muscle tone;
• limitation or complete absence of active movements in the limbs and body;
• damage mainly to the muscles of the arms and legs, but the muscles of the neck and torso may also be affected;
• spontaneous muscle pain syndrome;
• damage to the medulla oblongata;
• urinary disorders;
• damage and paralysis of the diaphragm and respiratory muscles.

During the recovery period of polio, which lasts up to 1 year, tendon reflexes are gradually activated and movements in individual muscle groups are restored. The mosaic nature of the lesion and uneven recovery causes the development of atrophy and muscle contractures, growth retardation of the affected limb, the formation of osteoporosis and bone tissue atrophy.

The residual period, or the period of residual effects, is characterized by the presence of persistent paresis and paralysis, accompanied by muscle atrophy and trophic disorders, the development of contractures and deformation in the affected limbs and parts of the body.

Preparalytic stage

It is characterized by a rather acute onset, high body temperature, general malaise, headache, gastrointestinal disorders, rhinitis, pharyngitis. This clinical picture persists for 3 days, then the condition normalizes for 2-4 days. Afterwards there comes a sharp deterioration in the condition with the same symptoms, but more pronounced intensity. The following signs are included:

• pain in legs, arms, back;
• decreased reflexes;
• increased sensitivity;
• decreased muscle strength;
• convulsions;
• confusion;
• excessive sweating;
• spots on the skin;
• "goose pimples".

Forecast for life

Mild forms of poliomyelitis (occurring without damage to the central nervous system and meningeal) pass without a trace. Severe paralytic forms can lead to permanent disability and death.

Thanks to many years of targeted vaccine prevention of polio, the structure of the disease is dominated by mild inapparent and abortive forms of infection; paralytic forms occur only in unvaccinated individuals.