Drinking Water Sanitisation and Live Vaccines – Live Vaccine’s Vulnerability To Water Sanitisation

“Probably the single greatest breakthrough in human health of the last millennium”

Big words for a substance made out of sodium chloride (salt water or brine) solution which has had an electric current passed through it. Yet chlorine is probably one of the most effective and affordable methods of sanitising drinking water in existence that has gone over the last 100 years from not only treating human water but also the drinking water in poultry houses.

What is Chlorine?

Salt water or sodium chloride is treated by a process called electrolysis; this is called the Chlor-alkali process. When an electrical current is ran through salt water the sodium separates from the chloride, an interesting fact; at one time 1% of the UK’s energy production was used for the production of chlorine.

How does Chlorine work

When chlorine is added to drinking water, a process takes place whereby the chlorine turns into hydrochlorous acid and hydrochlorous ions. When these compounds encounter the proteins that are present in a virus or a bacterial cell they have an oxidising effect on the protein and this causes a disorganisation of the cell structure and when a cells structure is damaged it is rendered unable to complete its function which in the case of a virus is to find a host in order to replicate.

How does this effect live vaccines?

A live vaccine is simply an attenuated (reduced in strength) version of the field virus or bacterial challenge. Now the most important word we need to focus on here is “live”, if a live vaccine is exposed to chlorine it will no longer have any effect of at worst it will be weakened and cause an uneven take within the flock leading to the passage of the virus from bird to bird. For a live vaccine to work as intended its critical each bird receives a protective dose. If the vaccine is not properly protected from chlorines then the proteins that make up the virus degrade rapidly, leading to not only to a poorly vaccinated flock but also a waste of time, money and potential profit from safeguarded production

The cell structure when examined under an electron microscope are incredibly similar and as such the chlorine will not discriminate between the vaccine or a wild strain virus and will destroy both equally as effectively.

This was in fact the greatest obstacle that the industry had to overcome as David Hodson Snr carried out extensive work on the mass administration of live vaccines throughout the 70’s, 80’s and 90’s. Looking to scientific work carried out by Dr. Jordan in the 1970’s at Liverpool university in which an infectious Bronchitis Vaccine virus was exposed to 0.02ppm chlorine for a period of 5 hours it was found that upon mixing the was a titre (concentration of virus particles) of 10/4.2 which is equivalent to 10,000 virus particle per ml. after an hour the reading was 10/1.8 which approx. 100 virus particle per ml and after 3 hours the vaccine was completely inactivated. What we see here is the vaccine being 100 times weaker after being exposed to chlorine for an hour.

Its really important to remember this work was carried out at 0.02ppm which was standard in tap water at the time, now government guidelines state that .5ppm is the upper limit in mains water and in animal water sanitisation we will use up to 2ppm.

At the time skimmed milk powder was used widely at a rate of 1 gram per litre consumed, this had the effect of the vaccine still reading 10/3.5 (1000 virus particle per ml) after 3 hours. There were issues however with using milk powder and they were, the production of biofilm due to the presence of proteins and lactose sugars in the water lines and header tank. When using a Dosatron pump a stock solution of 100 times the concentration was needed which would mean drinking water vaccination of 900L (average for 16,000 birds at peak production) would require a 900g of skimmed milk powder which would then causes blockages in the dosing pump and system.

Water Dye

During the 1980’s the entire industry was under pressure was a challenge of infectious bursal disease or as it commonly known, Gumboro. This virus has a high level of virulence and it was an ongoing battle to control. The mortality levels were severe and escalated daily until the reaching a peak and then the birds that had survived would have significant damage to the Bursa which is responsible for the programming of the immune system.

However out of this challenge came an understanding of how we were getting vaccination wrong. It was noted that even in the presence of vaccination the mortality would still be concentrated in the same areas, the ends of the water lines. We had mistakenly believed before that the vaccine solution would mix with the remaining water in the system and all birds would receive a protective dose.

This was wrong, it was not enough for the birds to drink the system dry as there was a residual amount of water within the system, approximately 1/3^rd. This would then be pushed to the end of the water lines so those birds would not receive a dose of vaccine.

This was discovered when Rosehill started to use commercial food dye produced by Anatol, it was a yellow substance and by being able to ensure the vaccine solution was present in the whole drinking line system Gumboro was brought under control.

This method of charging the water lines was adopted in all drinking water applications and is absolutely essential to effective vaccination.

Aviblue

Now we have an effective means of neutralising chlorine, stabilising the PH of the water and providing a visualisation of when each line is primed in a product developed for this purpose.

The key ingredients are;

Sodium Thiosulphate which reacts with chlorine and causes it to become sulphur and drop out of suspension.

Sodium Bicarbonate which raises the PH of the drinking water to 6.8-7.8. A PH (power of Hydrogen) of below 7 is classed as acid and now we have found that by lower the PH of the drinking water we have an effective means of sanitising water. The issue with vaccine application is an acidic environment will damage the vaccine and render it ineffective. Therefore, the inclusion of this compound creates a PH stable environment to allows minimal reduction in vaccine titre.

Therefore Aviblue is used across a large part of the layer and pullet rearing industry as it both a very cost effective means of ensuring effective vaccination and with the investment in vaccination either in lay or in rearing there is a significant requirement for live vaccines to be applied effectively.

Practical Guidelines to Live vaccine Application.

• Chlorination and acid dosing systems should be turned off 48 prior to vaccination.
• All vaccination equipment should be kept clean and for vaccine only.
• Live vaccine MUST be stored at between 2◦C – 8◦C
• The birds should be thirsted for a period of 1-2 hours prior to vaccination.
• The stock solution should allow a drinking period of 2 hour after thirsting (a calculation of 60L/1000 layers will allow for this)
• Aviblue must be used at the correct rate of 1 cap per 200L
• All water lines must be primed with vaccine solution and the clear water removed

Therefore, the recommended method of vaccination is as follows

Mixing

Vaccine should be prepared on a clean work surface wearing protective gloves. Measure 4 litres into a measuring jug, add 2g of Aviblue and whisk thoroughly. Open glass vaccine vials underwater and the MSD IB491 and MA5 vaccines can simply have the foil lid removed and empty these into the water. Mix thoroughly again until the vaccine has been complete dissolved.

Into the stock solution container measure the required amount of water, typically a 16,000 bird unit will require 20 litres in total at 2% and 10 litres at 1% so subtract the vaccine solution already mixed (4 litres) from this. Then add the required amount of Aviblue which will be 5 x 25g caps. Mix until the Aviblue is completed dissolved and then add the vaccine in the measuring jug. Again, thoroughly whisk.

Administration

Attach the pipe to the Dosatron – check the setting to ensure that it is correct for the stock solution. Turn OFF the Dosatron bypass and open the taps to allow the Dosatron unit to work. Ensure it is working prior to entering the shed.

The lights should be OFF during line priming as the birds drinking will slow the process and compromise an effective vaccination.

If an automatic flushing system is in place it is important to ensure it is correctly calibrated and vaccine is not wasted. This should be done beforehand.

There are two methods which can be used to charge the water lines dependant on the number of people available to help.

Method 1

If 1 person is carrying out the vaccination, simply open the taps at the end of the line and drain the water into buckets until the blue dye is present and then close the tap as each line is primed

Method 2

Using the flush valves have 1 person at each end of the water line. Once the tap at the end of the line is open a signal should be given to engage the flush. Once the dye is present at the end of the lines then a signal should be given to turn off the flush valve BEFORE the tap is closed. Otherwise if the tap is closed while the flush is on the water lines seals will be damaged.

Once all lines are successfully charged then the lights should be switched on and the birds allowed to drink. Keep birds in during the duration of the vaccine and 1 hour afterwards to ensure all the vaccine in the system has been consumed.

The key message I would like to be taken away from this is that the quality of the water for vaccination requires a temporary suspension of the acidic and chlorinated environment, as these compounds will not discriminate between the vaccine and the disease causing agent. Both will be destroyed which will result in compromised immunity, wasted time and wasted investment.

Remember the chlorine will permeate plastic and will be present in the lines even after the dosing system has been switched off for 48 hours, in a lower concentration but still highly damaging to live vaccine.